Tutorials
3-2-1 Backup: Automated, Encrypted, and Ransomware-Resistant
Automate, encrypt, and secure your 3-2-1 backup strategy with restic and a highly resilient storage target.
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245 posts
Step-by-step guides, practical examples and hands-on tutorials.
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Block Ads Across Your Entire Network: Why AdGuard Home Overtakes
Comparing AdGuard Home to Pi-hole, highlighting its superiority in performance, security, and management.
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I Stopped Paying for 1Password: My Own Password Vault with Vaultwarden
I'm explaining how I ended my 1Password subscription and set up my own password vault with Vaultwarden due to high costs and data control concerns.
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Home Server with N100: The Trade-offs of Low Power
How capable are Intel N100 processor mini PCs as home servers? The advantages and disadvantages of low power consumption, real-world...
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Securing a Server in the First 45 Minutes: VPS Hardening Checklist
I've shared my experiences on how to harden a new VPS with essential security steps in the first 45 minutes. SSH, firewall, and user management.
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6-Watt Home Server with N100 Mini PC: Homelab from Scratch in 2026
A step-by-step guide on how to start a homelab from scratch in 2026 by setting up a low-power (6W) home server with an Intel N100 processor mini PC.
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I Deleted Google Photos: All My Memories to My Own Server with Immich
I detailed my transition from Google Photos to Immich, the challenges I faced, and the specifics of photo management on my own server, step by step.
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Build Your Own AI Automation with n8n: Self-Hosted, No-Code Agent
Sharing my experience building self-hosted AI automations using n8n. Creating no-code agent flows, RAG, and multi-LLM integration steps.
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From Vibe Coding to Spec-Driven Development: Tasking AI with Spec Kit
Move beyond 'vibe coding' in software development and discover how to become more systematic and AI-friendly with Spec Kit. A detailed guide.
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Write Your Own MCP Server in 50 Lines: Real Tools for Your AI Agent
Connecting real-world tools to AI agents fundamentally changes their capabilities. I explain how I set up my own tool server and the challenges I faced.
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Local LLM with Ollama: A Real Alternative to Cloud Solutions?
I explore local LLM setup, performance, integration, and the advantages it offers over cloud solutions, based on my own experiences with Ollama.
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Keeping AI-Generated Code Secure: Balancing Risk and Efficiency
While AI-driven code generation speeds up development, managing security risks is critical. In this post, I share my strategies for safely using AI code in.
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8GB to 70B: A Real Hardware Guide for Local LLMs
A real-world hardware guide for running local LLMs. I explain the effects of VRAM, quantization, CPU, and disk speed based on my own experiences. Budget and…
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Shielding Against AI Voice Scams: Understanding a Real Conversation
Examines technical and behavioral defense mechanisms against AI voice cloning scams, and strategies for distinguishing a real voice from a fake one…
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Set Up Your Own ChatGPT: Ollama + Open WebUI for Data That Never
Ensure your data privacy by setting up your own local LLM with Ollama and Open WebUI. A comprehensive guide.
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Run Your Own LLM with Ollama: Local AI Setup in 5 Steps
In this guide, I'll walk you through setting up and running your own Large Language Model (LLM) on your local machine using Ollama. We'll do it in 5 simple.
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AI Prompt Security: Is the Same Protection Necessary for Every
Should prompt security strategies always be the same in AI applications? I share my flexible approaches and lessons learned for different scenarios.
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API Versioning Choices: Advantages and Disadvantages of 3 Approaches
I compare 3 common API versioning methods (URL Path, Query Parameter, Custom Header) for RESTful APIs. Which one is better in which situation...
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Switch Hardening: Is the Same Level of Detail Necessary for Every
I analyze the importance of switch hardening in network security and whether every device requires the same detailed configuration. Practical insights from my.
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AI Agent Tool-Use Architecture: Limitations and Cost Analysis
An in-depth analysis of AI agent tool-use architecture, its limitations, and costs. Featuring real-world scenarios and concrete data.
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Dependency Security in CI/CD: 3 Practical Cost Analyses
We examine the security of third-party dependencies used in our software projects and the associated costs for CI/CD processes with concrete examples.
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Idempotency in Distributed Systems: Even If You Process Multiple
Learn about idempotency in distributed systems, different approaches, and practical applications with Mustafa Erbay's experiences.
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RAG Retrieval Quality: Are Large Language Models Always Necessary?
A guide to building a high-performance, low-cost search infrastructure using lightweight re-rankers, BM25, and PostgreSQL instead of expensive LLMs in RAG.
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RAG Retrieval Quality: Are Large Models Really Necessary?
I examined the impact of large language models (LLMs) on retrieval quality in Retrieval-Augmented Generation (RAG) systems. Real-world scenarios and concrete.
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Zero Downtime Deployment: An Unnecessary Burden for Simple Projects?
Are Zero Downtime Deployment (ZDD) strategies truly necessary for small and medium-sized projects? In this post, I'll discuss the costs and trade-offs from my.
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My Favorite Linux Commands: My Silent Heroes in the Console
As a system architect for 20 years, I'm sharing the Linux commands that have saved me the most time, helped me solve the deepest problems, and are always at my.
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Are Grafana UI Alerts Insufficient? Alertmanager Installation and Why
Why does Grafana's built-in alerting system fall short? A deep dive into Alertmanager installation, its advantages, and the ideal system architecture.
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Monorepo Build Processes: Makefiles or Modern Build Tools?
Should monorepo build processes be managed with Makefiles or modern tools? A detailed comparison and experiences.
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Sampling in Distributed Tracing: Worth the Risk of Losing Detail?
I examine sampling strategies in distributed tracing, balancing cost and detail loss based on my own experiences. Which approach works when?
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Error Handling Choices: The Operational Burden of a Detailed Approach
I examine the operational cost, trade-offs, and real-world impacts of detailed error handling. How much detail is necessary in which situations?
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SNMP or NetFlow in Network Monitoring: Why Does the Choice Remain
I delve into the unending debate between SNMP and NetFlow in network monitoring, drawing from my own experiences. I discuss when I chose which, the trade-offs.
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ERP Integrations: Why the Point-to-Point Approach Falls Short?
Why point-to-point connections are insufficient in Enterprise Resource Planning (ERP) system integrations, illustrated with real-world examples and my.
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Eventual Consistency: The Operational Cost of Scalability
My personal experiences on choosing eventual consistency in distributed systems, the scalability advantages it brings, and the often overlooked operational.
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JWT Lifecycle vs. Secret Rotation: Which is More Secure?
Comparing JWT lifespans and secret rotation strategies, I'll share my experiences on which is more secure and practical in real-world scenarios.
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API Versioning Strategies: Pragmatic Approaches
API versioning is a challenge I frequently encounter in software architecture. In this post, I'll discuss different strategies, trade-offs, and my experiences.
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Eventual Consistency vs Strong Consistency: The Right Choice Guide
Understanding the differences, advantages, disadvantages, and key considerations for making the right choice between eventual consistency and strong.
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The Operational Overhead of Migrating from Monolith to Modular
I share my experiences with the operational challenges and costs encountered when migrating from a monolithic application to a modular structure.
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Why Unstructured Logging Falls Short: My Field Experiences
I examine the problems of unstructured logging I've encountered in systems, the parsing nightmare, and real-time analysis challenges through my own experiences.
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AI Agent Tool-Use Limits: When and Why to Stretch Them?
We explore when and why to stretch the tool usage limits of AI agents, with practical examples and technical analyses. We'll delve into trade-offs and...
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Build Cache Strategies: The Operational Burden of Speed
My experiences with the operational challenges I faced while shortening software build times and the trade-offs of different build cache strategies…
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JWT Revocation: Stateless Promise Meets Real-World Challenge
While JWT's stateless nature sounds appealing, I explore the challenges of token revocation in real-world scenarios and my solution approaches.
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The Cost of Offline-First Synchronization in Mobile Apps: A Pragmatic
We delve into the synchronization challenges, costs, and practical solutions brought by the offline-first architecture in mobile applications.
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Dependency Security: Stopping the Build or Warning?
Dependency security management is a critical issue in software projects. Zero tolerance by stopping the build, or flexibility with warnings? My field.
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BGP Route Flap Anatomy: Why It Happens, How to Fix It?
Understand the root causes of BGP route flap issues, diagnose them, and ensure your network's stability with effective solutions.
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The Cost of Offline-First Synchronization in Mobile Applications
I examine the real operational cost of building an offline-first synchronization architecture in mobile projects, through the lens of databases, networking.
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API Versioning: URI vs Header – Which Is More Practical?
I compare the URI and Header approaches to API versioning with real‑world examples, discussing trade‑offs and practical implementations.
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Log Level Strategy: How to Make the Right Choices in a Production
What should be considered when defining a log level strategy in production environments? Which log level should be used when? I'll explain with my experiences.
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Mobile Push Notifications: Firebase or Your Own Solution? Detailed…
Comparing push notification solutions for mobile apps through Firebase and custom-developed alternatives, covering cost, flexibility, and…
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The Anatomy of VLAN Segmentation: Foundations of Proper Design
Learn step-by-step how to design VLAN segmentation to improve network security and performance. Real-world scenarios and practical tips.
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AI Prompt Injection Defense: Building Effective Strategies in 5 Steps
Develop actionable and effective strategies in 5 steps to protect Large Language Models (LLMs) from Prompt Injection attacks. Practical solutions based on my.
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The Burden of API Versioning: URI or Header?
I compare API versioning strategies, specifically URI and Header-based approaches, using my own experiences. In which scenarios does each make more sense?
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BGP Route Flap Damping: A Solution or a New Problem?
Deep dive into the BGP route flap damping mechanism. Explore its actual benefits, potential drawbacks, and real-world implications in network engineering.
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Seamless Deployment: Blue/Green vs Canary Trade-off Analysis
This post provides a technical deep dive into Blue/Green and Canary seamless deployment strategies, examining their trade-offs and real-world applications.
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Vector Database Selection: Balancing Cost and Performance
Comparing PGVector, Qdrant, and Milvus to reduce memory costs and achieve performance balance in vector search projects.
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Managing AI Agent Tool-Use Limits in 3 Steps
Learn how to manage the boundaries of AI agents' tool usage in 3 steps to ensure these tools are used safely, efficiently, and in a controlled manner...
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App Size Optimization in Mobile Apps: Practical Approaches
Practical methods and trade-offs I use to reduce mobile app size. How I optimized code, resources, and distribution processes.
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Multi-Tenant ERP: The Risks of a Shared Schema
An in-depth look at why the shared schema approach in multi-tenant ERP systems is risky, complete with real-world examples and technical details.
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RBAC or ABAC: Which Authorization Model?
Comparing RBAC and ABAC among authorization models. Which is more suitable for which scenario, based on my production environment experiences...
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SAST vs DAST: Which Should Come First in Application Security?
Discover the differences between SAST and DAST tools in application security, when to use them, and why both are critical, based on my own experiences...
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JWT Refresh and Revocation Mechanisms: The State of Security Practices
I'm sharing my experiences on the role of JWT (JSON Web Token) refresh and revocation processes in security practices and their implementation strategies.
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Prompt Injection Defenses: Cost and Real-World Effectiveness Analysis
I examine the measures I've taken against prompt injection in AI applications, their costs, and their practical effectiveness based on my own experiences.
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Mobile UI: Native or Cross-Platform? The Right Decision
Exploring the fundamental differences between Native and Cross-Platform approaches for UI development in mobile apps, drawing from my experiences.
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RAG Retrieval: Is High Quality Essential for Every Project?
I delve into the importance of retrieval quality in Retrieval-Augmented Generation (RAG) systems with concrete examples and in-depth analysis.
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Anatomy of Database Index Structures: Fundamentals of Query
A detailed examination of database index structures (B-tree, GIN, BRIN) and strategies for enhancing query performance. With real-world scenarios and concrete.
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The Cost of Cross-Platform Development: Native Module Integration
I share my experiences regarding the challenges and costs of native module integration in cross-platform frameworks like Flutter.
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Idempotency in Distributed Systems: 3 Methods for Fault Tolerance
Learn about the concept of idempotency in distributed systems and 3 effective methods to ensure operation repeatability and data consistency in the face of.
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BGP Route Flap Management: Effective Prevention in 3 Steps
A practical guide to understanding, diagnosing, and effectively managing BGP route flap issues in 3 steps.
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Distributed Locks vs. Leased Locks: The Right Choice in Resource
This article delves deep into distributed locks and leased lock mechanisms used for managing access to shared resources in distributed systems,...
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Restricting Tool Usage in AI Agents: Secure Design in 3 Steps
How do you control the tool usage of AI agents? Secure agent architecture with schema hardening, isolation, and RBAC.
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JWT Storage: LocalStorage or HttpOnly Cookie?
I explore the intricacies of securely storing JWT tokens in web applications, comparing LocalStorage and HttpOnly Cookies.
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Idempotency Design in Distributed Systems: A Modern Approach
How I design idempotency keys and database strategies to resolve the 'did it go through?' chaos following API request timeouts.
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Logs vs. Metrics: Which is More Effective for Troubleshooting?
Explore the differences between logs and metrics for troubleshooting, their strengths and weaknesses, and when to use each in detail.
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Build Cache Management in CI/CD: 3 Practical Strategies
Effective build cache management strategies to shorten build times in your CI/CD pipelines. Sharing my experiences.
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Build Cache Management in CI/CD: 3 Practical Approaches
Learn the importance of build cache management and 3 effective methods to shorten build times in your CI/CD pipelines. Reduce costs, improve developer...
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Offline-First Synchronization Strategies in Mobile Applications
In-depth strategies and practical approaches for data synchronization, offline operation, and performance optimization in your mobile applications.
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Retries and Idempotency in AI Pipelines: A Guide to Error Handling
I explain how I design and implement retry and idempotency mechanisms to effectively manage errors encountered in AI pipelines.
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7.6 GB VPS Swap Fire with Docker: A Kernel Patch Nightmare
A practical guide to swap issues encountered when using Docker on small VPS instances and kernel patch solutions. Detailed analysis with my experiences.
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✍️ Hand-written
Swap Fire: My Kubernetes Experiment on a 7.6 GB VPS
A pragmatic analysis of swap memory issues and their solutions encountered while experimenting with Kubernetes on a small VPS.
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Docker Container Network Traffic: Monitoring and Optimization on My
I'm detailing step-by-step how I monitor and optimize network traffic for Docker containers running on my VPS. Performance tips and practical commands included.
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Why Are My Docker Containers Slow? A Monitoring Guide for My Own VPS
A practical guide to monitoring the performance of Docker containers on your own VPS and finding the root causes of slowdowns. Systemd, cgroup, and journald…
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Docker Deploy on VPS: Nginx Strategies for Zero Downtime
Mustafa Erbay details the technical aspects and strategies for achieving zero-downtime deployments using Nginx for Dockerized applications on a VPS.
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Guide to Detecting and Limiting Resource-Hog Containers on a VPS
I'm sharing a step-by-step guide on how I identified resource consumption issues on my own VPS and applied limits to Docker containers.
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Your App is 'Up' But Not Working: Docker Healthchecks
I explain step-by-step how to write robust health checks (HEALTHCHECK) for situations where Docker containers appear 'up' but the application isn't actually.
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Securely Deploying an SQLite Database to a Docker Container with
A guide to securely deploying an SQLite database to a Docker container using GitHub Actions.
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Docker Disk Storage Wars: A Guide to Data Integrity on VPS
I explain how I manage Docker disk space on my own VPS, ensure data integrity, and the problems I've encountered.
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Nginx Reverse Proxy: Managing Multiple Docker Services on a Single VPS
A step-by-step guide on how I manage multiple Docker applications on a single VPS using Nginx reverse proxy, and the challenges I encountered.
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The Invisible Wars of Environment Variable Management: Hidden…
Discover why environment variable management is so critical, the common nightmares, and effective strategies to win these hidden wars. From application...
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BGP Neighbor Wars in Network Infrastructure: An Operational Nightmare
Learn what BGP neighbor wars are, why they emerge, and practical strategies to prevent this operational nightmare. Keep your network stable.
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The Network's Blind Spot: Chasing MTU Mismatches
Discover the MTU mismatch behind mysterious issues affecting your network performance. In this detailed guide, learn what MTU is, how to diagnose problems, and…
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The Ephemeral Storage Trap in Cloud Infrastructure: An SRE…
Explore the risks of ephemeral storage in cloud platforms and the best practices to prevent data loss from an SRE perspective.
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Hidden Network Segmentation: An SRE's Security Battle
Hidden network segmentation is both a security necessity and an operational challenge for SREs. In this article, we dig deep into the topic from an SRE…
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The Cost of a Single Bad Decision in System Architecture
Learn the destructive effects of a single wrong decision in system architecture and how to avoid these mistakes.
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Resource Leaks in Serverless Compute: A Hidden Operational Nightmare
A deep look at the hidden impact of resource leaks in serverless (serverless) compute platforms on operational costs, and how to fight back…
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The Load Balancer's Silent Betrayal: Misrouted Traffic
A deep look at how load balancer (Load Balancer) misconfigurations affect system performance and the issues that cause traffic to get misrouted.
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The Silent Decay of Cloud Firewall Rules: An Operational…
Learn how cloud firewall rules degrade over time and how that decay turns into an operational nightmare.
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Hidden Dependency Hell in the CI/CD Pipeline: An Automation Nightmare
Learn the issues that hidden dependencies cause in your CI/CD pipelines, their types, detection strategies, and lasting solutions. End the automation…
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The Fragility of the Distributed Database Shard Key
I unpack the critical role of the shard key in distributed databases, the risks it carries (hotspots, data skew), and the strategies to keep that fragility…
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The Hidden Communication Crisis in Container Networks: CNI Wars
Explore the critical role of CNI in Kubernetes environments, the different CNI options, and the hidden crises around performance, security, and complexity…
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The Prometheus High Cardinality Crisis: A Silent Metric Invasion
A guide to understanding, detecting, and managing the high cardinality crisis in Prometheus. Optimize your metrics to keep system performance and costs under…
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The Anatomy of Unscalable Database Decisions in System Architecture
A deep look at the long-term effects of database choices in system architecture and the scalability traps they create. The cost of bad decisions and…
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Hidden Kernel Panic Battles: System Betrayal in Production
A field guide to understanding, preventing, and recovering from kernel panics in production. How to keep your systems stable.
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Hunting Hidden Blackholes in Production Networks: An Anatomy of…
Find the invisible blackholes in your production network. Understand why traffic disappears, and walk through how to debug it step by step.
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Redis Sharding: The Hidden Wars in Production and Its Dark Side
Explore the complexity, challenges, and hidden production battles of Redis sharding. We shed light on the dark side of sharding.
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Spot Instance Optimization: A Hidden Cost Trap in Production
While Spot Instances offer cost savings in cloud computing, in production environments they can create hidden cost traps with unexpected interruptions. In…
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Hunting Poison Messages in Message Queues: The Silent Nightmare of…
Learn about the 'poison message' problem that arises in message queues and the strategies to deal with it. Protect the health of your production environment.
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Circuit Breaker Crisis in Production: The Fragility of Microservices
Misapplying or skipping the circuit breaker pattern in microservice architectures can cause serious crises in production environments. In this post…
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Distributed Lock Deadlock in Production: The Silent Betrayal of…
Understanding the deadlocks that distributed lock mechanisms can cause in microservice architectures, and grasping this silent betrayal, is critically…
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Split-Brain Scenarios in Production: Anatomy of a Battle
A detailed look at split-brain — one of the most critical issues in distributed systems — its causes, its impact, and the strategies for keeping it at bay.
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Cloud Firewall Policy Conflicts: An Operational Nightmare
An in-depth look at the operational impact of cloud firewall policy conflicts and how to resolve these issues.
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The Cache Invalidation Dead End in Large-Scale Systems
An in-depth look at cache invalidation problems frequently encountered in large-scale systems and the solutions that actually work.
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Leader Election in Distributed Systems: A Critical Mechanism in Crisis
An in-depth look at the importance of the Leader Election algorithm in distributed systems and how it kicks in when things go sideways.
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The Hidden Trap of Legacy PostgreSQL Replication: Why You Need to…
Learn the potential pitfalls of setting up replication on older PostgreSQL versions, and how to avoid them. Stay safe and stable…
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IaC Drift Management: Unexpected Infrastructure Discrepancies and
IaC Drift Management prevents your infrastructure from deviating from your code. Learn the causes, risks, and strategies for detecting and correcting drift.
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Hidden IPVS Issues in Kubernetes Clusters and How to Solve Them
Take a deep dive into the IPVS issues you run into in critical Kubernetes clusters. This guide walks through the subtleties of IPVS and the performance…
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The Distributed Cache Invalidation Dilemma: Anatomy of…
Take a deep look at distributed cache invalidation strategies in distributed systems and the problems caused by inconsistent data. Solutions and best…
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A Hidden Resource Exhaustion War: The Deadly Dance of Containers
Learn about the hidden resource-exhaustion war containers fight, and how to manage this deadly dance. Performance optimization and stability included…
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Kubernetes Service Discovery Crisis: The Dark Side of DNS
Are you wrestling with service discovery issues in Kubernetes? Explore the limitations of DNS and how to overcome these challenges.
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Hidden Network Policy Crises in Production: Kubernetes War Stories
Overlooked details in Kubernetes Network Policies can spark unexpected crises in production. In this article we'll dig into common pitfalls and…
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Virtual Server Hardware Overcommit: The Hidden Threat to Performance
Learn how hardware overcommit on virtual servers quietly tanks performance — and how to keep your infrastructure out of that hidden swamp.
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The Thundering Herd Problem in System Architecture: Crisis Management
Get a deep understanding of the thundering herd problem in system architecture — what it is, why it happens, and how to solve it. Keep your systems stable…
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Storage I/O Latency Battles in Legacy Virtualization
Take a detailed look at the Storage I/O Latency problems you run into with legacy virtualization infrastructure, their causes, and the strategies for fixing…
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Kubernetes Network Policy Errors: A Battlefield at Midnight...
A comprehensive guide to fighting Kubernetes Network Policy errors. Understand common pitfalls and save your night with practical solutions.
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Pet and Cattle Models in Cloud Architecture: The Scaling Dilemma
Learn the 'Pet' and 'Cattle' models in cloud architecture, the scaling challenges, and modern approaches with Mustafa Erbay's perspective.
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How a Hidden DNS Bug Brought Down a Network Architecture: A Case Study
Learn through a case study how a hidden DNS bug threatening network architectures can spiral into a full-blown disaster. Don't miss this deep dive.
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Observability Failure: The Hidden Causes Behind Critical…
Discover the overlooked causes behind production outages. Learn the impact of observability failure on critical systems and how to fix it.
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RAM Exhaustion and the OOM Killer: How to Prevent Sudden Crashes…
Take a deep look at RAM exhaustion and the Linux OOM Killer mechanism that causes sudden crashes in production. Diagnosis, prevention, and resolution…
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Leadership in Distributed Systems: Architectural Decisions in a Crisis
Discover the critical role of leadership in architectural decision-making during crises in distributed systems, plus the strategies that work.
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Origin Shield Issues in Cloud Native CDNs: A Cache Stampede Hunt
Learn about the cache stampede problems that Origin Shield can cause in Cloud Native CDNs, and how to solve them.
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The Micro-Segmentation Trap: Unexpected Network Outages
A look at the security benefits of micro-segmentation, the unexpected network outages it triggers when applied incorrectly, the root causes, and how to fix…
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Session Recording on the Bastion: tlog + sudo I/O + SSH Audit Pipeline
Making privileged access visible on the bastion: tlog/sudo I/O logging, the access model and a SIEM pipeline.
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Cache Stampede in Front of the CDN: Origin Server Loading Wars
Explore the Cache Stampede problem in front of CDNs, its causes, and effective strategies to avoid overloading the origin server.
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Canary Deployments on Cloud Native Infrastructure and the…
Explore the Deployment Blackhole problems frequently encountered during canary deployments on cloud-native infrastructure, along with proposed remedies.
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Kernel Tuning and eBPF Defense Against SYN Flood Attacks
Learn how to harden your servers against SYN Flood attacks with kernel tuning and eBPF. This in-depth guide walks through deep technical…
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Clock Drift in Distributed Systems: The Hidden Danger of Time
Discover the critical importance of time synchronization in distributed systems and the hidden dangers caused by clock drift. Explore NTP, PTP, logical…
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Reducing Layer-2 Insider Threats on Switches with DHCP Snooping + DAI
A staged playbook for rolling out DHCP Snooping, DAI, and IP Source Guard on access networks to defend against rogue DHCP, ARP spoofing, and IP impersonation.
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Defense Strategies Against Kubernetes DNS Cache Poisoning
Learn effective defense strategies against DNS cache poisoning attacks in Kubernetes environments. Discover methods to strengthen your security.
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Kubernetes Pod-to-Pod Network Policies Battles: Securing the Mesh…
Learn step by step how to secure pod-to-pod network communication in Kubernetes with Network Policies. A detailed guide with examples.
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Secure Network Device Monitoring with SNMPv3: Auth, Encryption, ACL
A guide to leaving SNMPv2c community strings behind and making network device monitoring secure and operable with SNMPv3 authPriv, views and ACLs.
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Core Dump Management and Privacy Runbook with systemd-coredump
Collecting core dumps in production: limits, retention, encryption, access and a practical runbook for safe analysis during an incident.
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Kubernetes API Server Audit Log: Policy and SIEM Pipeline
Collecting Kubernetes audit logs without drowning in noise: a practical approach to policy, retention, masking and SIEM correlation.
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PostgreSQL WAL Archiving and a Point-in-Time Recovery Drill
A guide to building PostgreSQL PITR practice with production discipline: WAL archiving, recovery time targets and safe restoration steps.
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Service Discovery with Consul: Health Checks and the DNS Interface
A guide to building an operable service discovery layer with Consul through health-driven service registration and the DNS interface.
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IPv6-Only Migration with NAT64/DNS64: Runbook and Design
Design, risks, monitoring, and a practical runbook for managing IPv6-only clients' IPv4 dependencies using DNS64 + NAT64.
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Centralized Logging with systemd-journal-remote: mTLS and Retention
A practical setup and runbook for shipping journald logs over mTLS to a central collector — without adding agents — while running a disciplined disk budget…
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Kubernetes Control Plane Certificate Expiry: A Runbook
When API Server access suddenly breaks with x509 errors; certificate renewal and safe recovery steps for kubeadm-based clusters.
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Linux kdump: Kernel Panic Crash Dump and Triage Runbook
Walks through kdump installation, validation and a sustainable production dump retention flow so you can capture vmcore and triage quickly when a kernel panics.
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Linux SoftIRQ Saturation and IRQ Affinity Runbook
Quick triage, measurement and safe tuning steps (ring, queue, IRQ, RPS) under packet drops, high softirq load and ksoftirqd pressure.
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Designing a Telemetry Pipeline with OpenTelemetry Collector
Treating Collector not just as an agent but as a central telemetry backbone for sampling, redaction, routing and multi-destination delivery.
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Golden Image Pipeline with Packer: CIS Baseline and Patch Strategy
A golden image approach that hardens and tests the server image at build-time, accelerating patch, drift and emergency CVE workflows.
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PostgreSQL HA: Failover Runbook with Patroni
Walks through quorum, replication lag, switchover/failover testing and recovery steps when running PostgreSQL high availability with Patroni, in runbook form.
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Zero-Downtime Restart with systemd Socket Activation
A runbook for shrinking deploy impact by separating connection acceptance into a socket unit, so the listening port never drops during service restarts.
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✍️ Hand-written
Self-Healing Services with systemd Watchdog
Reduce 'stuck but not dead' failures with systemd WatchdogSec + notify: unit configuration, restart policy, and alarm integration.
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Packet Capture in Production with tcpdump: A Runbook
Practical tcpdump techniques for collecting minimal-yet-sufficient packet evidence during incidents: filters, snaplen, ring buffer, privacy, and handover…
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Terraform CI Guardrails: Plan/Apply, Drift, and Policy Check
Balancing safety and speed in IaC: a guide to managing prod changes through plan/apply separation, drift detection, policy-as-code, and approval flows.
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vSphere/ESXi Host Patch: Maintenance Wave and Rollback Runbook
Manage the ESXi host patch process with ring-based maintenance waves, control capacity/HA risk, and establish safe remediation and rollback discipline.
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Centralized Logging with Windows Event Forwarding (WEF)
Subscriptions, health checks, and a triage runbook to centrally collect and validate security and operations signals in Windows domain environments using WEF.
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Local Admin Password Rotation with Windows LAPS (AD/Entra)
Cut down lateral movement risk by automatically rotating local admin passwords across servers and clients; build secure operations on top of delegation and…
Tutorials
An NTS and NTP Hardening Runbook with chrony
A practical chrony runbook for enterprise servers covering secure NTP (NTS), access restrictions, verification commands, and alarm thresholds.
Tutorials
Server Inventory and Security Signals with FleetDM + osquery
Turn 'what's on which server?' into a living inventory; a guide for scaling osquery queries with FleetDM into operational and security signal.
Tutorials
A Safe Migration Runbook from iptables to nftables
Reduce risk while moving production firewall rule sets from iptables to nftables using observability, wave-based rollout, and fast rollback.
Tutorials
SLO-Driven Load Testing with k6: Capacity Baselines and Release Gates
A practical approach that turns load testing from a peak-RPS race into an SLO-driven (latency/error) capacity baseline and a CI release gate.
Tutorials
Phased Hardening of Kubernetes with PSA + Kyverno
Roll out security guardrails in production clusters gradually with Pod Security Admission (PSA) and Kyverno: an audit→warn→enforce plan.
Tutorials
Kubernetes RBAC: Least Privilege + Break-Glass Model
A practical RBAC framework for role design, identity integration, and time-boxed emergency access (break-glass) without depending on cluster-admin.
Tutorials
A Maintenance-Wave Runbook for Firmware Upgrades on Enterprise…
A runbook that turns firmware upgrade work into a repeatable maintenance rhythm with inventory, ring/wave approach, validation metrics, and a rollback…
Tutorials
A WORM Backup Layer Runbook with S3 Object Lock
Practical steps for building a WORM (Write Once Read Many) layer against ransomware and accidental deletion using S3 Object Lock, retention policies, and…
Tutorials
GitOps Secrets Management with SOPS + age
A practical SOPS + age setup and operational discipline for keeping encrypted secrets in Git and decrypting them safely inside CI/CD and the cluster.
Tutorials
AAA on Network Devices with TACACS+: Command Authorization and Audit
A TACACS+ approach that reduces local admin sprawl on network devices and turns session traces into proof through roles, command authorization, and accounting.
Tutorials
A Pre-Validation Pipeline for Network Changes with Batfish
A practical Batfish flow that validates routing/ACL changes before they reach production via 'snapshot + question set,' catching human error early.
Tutorials
Kubernetes Admission Webhook Timeouts: A Runbook for Frozen Deploys
Field runbook to rapidly triage hung deploys caused by Validating/Mutating webhook latency and apply a risk-controlled mitigation.
Tutorials
Kubernetes ETCD Quorum Loss: Triage and Recovery Runbook
A runbook for quickly diagnosing ETCD quorum during API 5xx/timeout storms and walking through safe recovery steps via snapshot restore.
Tutorials
Workload Identity and mTLS with SPIFFE/SPIRE
A guide to wiring service-to-service mTLS through SPIFFE identities and SPIRE-issued short-lived certificates instead of relying on IPs and static secrets.
Tutorials
SSH + FIDO2: Phishing-Resistant Admin Access (Practical Runbook)
Hardening admin access with OpenSSH security keys (ed25519-sk) using PIN + touch confirmation, while keeping break-glass scenarios intact.
Tutorials
Protecting the Kubernetes Control Plane with API Priority and Fairness
A practical APF setup that prioritizes critical traffic and fairly queues noisy callers, lowering the risk of API server overload.
Tutorials
Designing Maintenance Waves for Kubernetes Node OS Patching
Roll out node patches in maintenance waves rather than all-at-once: drain, PDB, parallelism, and a safe rollback path.
Tutorials
Network Drift with NetBox + Nornir: An Approval-Driven Remediation…
Detect configuration drift, approve fixes through Git, and apply them under control: source of truth → report → PR → rollout.
Tutorials
Short-Lived SSH Certificates with an OpenSSH CA
An OpenSSH CA-based approach to set up auditable, time-bound SSH access in place of shared bastion accounts and long-lived keys.
Tutorials
Hardening Services with systemd Sandboxing (ProtectSystem…
Constrain services into a tighter permission set without changing the application itself: filesystem, capability, syscall, and network limits.
Tutorials
Enterprise NTP Architecture with Chrony, and Drift Alerting
Chrony settings, firewall recommendations, and drift/loss alarms to design a hierarchical and secure time synchronization.
Tutorials
Fast Failover with BFD on FRR: A Practical Guide
An approach to enabling BFD with FRR (BGP/OSPF) to generate fast signals when the link looks up but traffic isn't flowing (blackhole).
Tutorials
Operational Runbook for JWKS Key Rotation
A runbook to triage the 401 wave (kid mismatch/JWKS cache) that occurs during JWT key rotation, and to set up safe overlap/caching strategy.
Tutorials
Privileged Command Monitoring Runbook on Linux with Auditd
A practical approach that makes privileged operations observable and auditable in production using sudo, auditd rules, and log forwarding.
Tutorials
Linux Conntrack Capacity Planning and Alerting Runbook
A practical guide for generating signals before the nf_conntrack table fills up, applying safe sysctl tuning, and recovering in a controlled way during an…
Tutorials
Linux TCP Backlog and SYN Flood Resilience Runbook
A runbook to triage the connect timeout crisis when the SYN backlog/accept queue fills up, apply rapid mitigation, and design lasting resilience.
Tutorials
High Availability and Split-Brain Runbook with Redis Sentinel
A field-ready runbook for operationally managing quorum, failover, and split-brain risk in a Redis Sentinel-based HA setup.
Tutorials
Cgroup v2 Memory Pressure Runbook with systemd-oomd
PSI, systemd-oomd policy, testing, and recovery steps to catch a node OOM crisis early and evict workloads in a controlled way.
Tutorials
systemd-Based Service Containerisation with Podman Quadlet
A practical way to manage server services with systemd and Podman Quadlet, free from the Docker daemon dependency.
Tutorials
Sensitive-Data Masking Pipeline for Logs with Vector and VRL
A practical Vector and VRL based approach for cleaning sensitive fields out of a centralised log stream before they reach the destination.
Tutorials
Service-Based Linux Hardening with AppArmor
An AppArmor guide for securing server services through process-level constraints rather than generic hardening.
Tutorials
Multi-Point Service Health Monitoring with Blackbox Exporter
An installation guide that pushes a real reachability signal into Prometheus by running HTTP, TCP, and TLS checks from multiple network locations.
Tutorials
Designing an Enterprise Management Network Overlay with Headscale
A Headscale-based management network overlay guide for providing controlled access to scattered servers and management endpoints.
Tutorials
Continuous Vulnerability Validation on Internal Assets with Nuclei
A practical Nuclei approach for scanning internal network services with low noise and tying validated findings to your operations workflow.
Tutorials
Tail Sampling Design in the OpenTelemetry Collector
A guide that explains how to set up tail sampling to lower cost on high-volume trace data while preserving the critical flows.
Tutorials
Short-Lived Certificate Automation for Internal Services with step-ca
A guide that explains a step-ca based short-lived TLS certificate generation flow for cutting long-lived certificate burden between internal services.
Tutorials
An SBOM-Based Image Admission Gate with Syft and Grype
A practical guide to admitting container images not just by a CVE list, but by component inventory and policy threshold.
Tutorials
A Guide to Container Supply Chain Signing with Cosign
A practical and enterprise-friendly setup guide for signing container images with Cosign and verifying them in the delivery pipeline.
Tutorials
An Egress Traffic Policy Layer with nftables
A guide describing how to set up an nftables-based egress policy layer to control which destinations servers can reach in the outside world.
Tutorials
A Telemetry Filtering Layer with the OpenTelemetry Collector
A guide describing how to set up filtering and routing on the OpenTelemetry Collector to reduce unnecessary volume in metric, log, and trace flows.
Tutorials
A Guide to Tenant-Based State Separation with OpenTofu
A practical guide to splitting OpenTofu state in order to preserve tenant, environment, and ownership boundaries in enterprise infrastructure.
Tutorials
Reliable Remote Log Transport with Rsyslog and RELP
An rsyslog and RELP-based setup that keeps critical logs intact through TCP drops as they ship to a central system.
Tutorials
Building a Link Latency Baseline with SmokePing
A SmokePing guide for making latency and jitter behaviour visible across branch, data center, and cloud connections.
Tutorials
Designing a Route Reflector Lab with Bird 2
Building a Bird 2-based route reflector laboratory to safely experiment with internal BGP topologies.
Tutorials
Internal API Authorization Chain with Envoy ext_authz
A secure authorization pipeline you can build with the Envoy ext_authz filter to separate identity, policy, and decision logging on internal service traffic.
Tutorials
Tiered Log Retention with Grafana Loki
A cost-focused retention guide for designing hot, warm, and archive log tiers on Loki.
Tutorials
Publishing Services on Bare Metal Kubernetes with MetalLB
A clear design framework based on MetalLB for publishing services on bare metal Kubernetes clusters without a cloud load balancer.
Tutorials
Policy-Based Routing and Backup Link Design with Netplan
Set up a policy-based routing layout on Linux servers with Netplan that separates primary and secondary uplinks based on source network.
Tutorials
REST API Design Principles
Practical rules for sustainable REST API design in production — from resource modelling to idempotency, pagination, and the error contract.
Tutorials
East-West Traffic Profiling with Suricata: A Practical Guide
A low-friction profiling approach with Suricata to make service-to-service traffic visible inside the data center.
Tutorials
Regional DNS Cache and Forwarder Separation with Unbound
A clean guide for separating resolution traffic across enterprise segments by configuring cache, forwarder, and access control with Unbound.
Tutorials
Just-in-Time Access to the Management Network with WireGuard
A practical WireGuard-based approach to building short-lived, auditable management access instead of permanent VPN accounts.
Tutorials
Monitoring Time Drift on Servers with Chrony
A Chrony-based guide to making clock drift visible across distributed Linux servers and reducing operational risk.
Tutorials
Network Flow Observability with eBPF and SLO Correlation
An approach to monitoring network flows at the kernel level and correlating them with service latency and error budget signals.
Tutorials
BGP Failover Lab Guide with FRRouting
Steps for validating BGP failover behavior in a lab for servers or edge environments using dual uplinks.
Tutorials
Long-Term Metric Retention with Grafana Mimir
A practical guide to designing long-term metric retention in multi-tenant environments without hitting the Prometheus bottleneck.
Tutorials
Passive Health Checks for Internal Services with HAProxy
An HAProxy approach to catching internal service failures from real request flow without adding active probe traffic.
Tutorials
VRRP Failover for the Management Plane with Keepalived
A Keepalived-based VRRP failover approach for reducing single-VIP dependency in internal management services.
Tutorials
PostgreSQL Performance Optimization
A guide to speeding up PostgreSQL in production by measuring slow queries, finding root causes with EXPLAIN, designing the right indexes, and maintaining…
Tutorials
Protecting Management APIs with mTLS on Nginx
A simple and auditable mTLS setup on Nginx for protecting management APIs with client certificates.
Tutorials
A Centralised Log Collection Pipeline with Vector
A practical Vector-based setup approach for collecting and routing application, syslog, and infrastructure logs through a single stream.
Tutorials
CI/CD Pipeline Design and Best Practices
A guide to designing the CI/CD pipeline as build-test-gate-deploy for fast feedback, safe releases, and low-risk deploys.
Tutorials
Agent Consolidation with Grafana Alloy
A Grafana Alloy based approach for unifying the chaos of node exporter, log agent, and telemetry collector into a single pipeline.
Tutorials
IPAM and Inventory Automation with NetBox
A NetBox approach for moving the network address plan and data center inventory out of ticket spreadsheets and into an automation-friendly model.
Tutorials
Detecting Server Configuration Drift with Ansible
A guide to Ansible-based drift auditing for measuring and reporting deviations from the expected state on Linux servers.
Tutorials
A Server Hardening Baseline with Ansible
A guide to making your Linux server security baseline repeatable and auditable with Ansible.
Tutorials
Safe Version Promotion with Argo CD Image Updater
A guide for setting up a safe promotion model on a GitOps pipeline without leaving container versions to uncontrolled automation.
Tutorials
Gradually Tightening Kubernetes Network Policies with Cilium
A guide to moving Kubernetes network policy from observability into enforced control without breaking production.
Tutorials
Runtime Security Observation with Falco
A Falco-based setup guide for surfacing suspicious runtime behavior across Linux and Kubernetes environments.
Tutorials
Effective Version Control with Git and GitHub
A field guide to Git/GitHub practices — branch strategy, PR review discipline, clean commit history, and release flow.
Tutorials
Privileged Access with Short-Lived Certificates
A guide to managing privileged access safely by using short-lived certificates instead of permanent SSH keys.
Tutorials
mTLS-Based Service Identity Verification with Nginx
A practical Nginx-based approach to verifying service identity through mutual TLS for internal service traffic.
Tutorials
An OPA Pipeline for Terraform Plan Policies
A practical guide to gating infrastructure changes through policy by inspecting Terraform plan output with OPA.
Tutorials
A Centralized Log Routing Pipeline with Vector
A practical Vector-based setup for filtering, enriching, and routing scattered log streams to multiple destinations.
Tutorials
Docker Container Security Guide
From image supply chain to runtime hardening, a practical checklist and runbook for running Docker containers safely in production.
Tutorials
Observing Linux Network Flows with eBPF
A guide for tracking flows, latency, and connection behavior on Linux servers with eBPF without drowning in packet capture.
Tutorials
Multi-Environment Promotion Pipeline with GitOps
A practical, GitOps-based guide for building a controlled promotion flow across development, test, and production environments.
Tutorials
External Secrets Flow for Kubernetes Secret Rotation
A guide based on External Secrets for pulling secret data from a central vault and applying rotation in Kubernetes environments.
Tutorials
Designing Prometheus Alert Routing
A guide for building an Alertmanager routing model that reduces misdirected alerts and accelerates incident response.
Tutorials
Publishing Internal Services and Automating TLS with Traefik
A Traefik-based guide for safely publishing internal services and automating the certificate lifecycle.
Tutorials
Machine Identity Management with Vault
A guide to designing short-lived machine identities for servers, services, and automation users instead of static secrets.
Tutorials
Immutable Infrastructure Discipline on Linux Servers
An approach for moving server configuration out of manual labour and into a safe, repeatable automation flow.
Tutorials
End-to-End Observability Pipeline with OpenTelemetry
An OpenTelemetry-based observability architecture that brings metric, log and trace data into a single standard.
Tutorials
Cloudflare Tunnel and Reverse Proxy Guide
How to set up a secure reverse proxy structure that hides your origin IP using Cloudflare Tunnel.
Tutorials
Building a Modern Blog with Astro
How to build a fast, SEO-friendly, and high-performance blog with the Astro framework.
Tutorials
Secret Rotation Strategies: The Security Cost of Automation
I delve into secret rotation strategies, the impact of automation on security, and practical approaches.
Tutorials
Log Level Decisions: The Anatomy of DEBUG, INFO, and ERROR Strategies
Managing system and application log levels (DEBUG, INFO, ERROR) correctly is critical for troubleshooting and operational efficiency. In this guide, based on.