DevOps

Your application says it’s running. But is it actually working? Health checks answer that question. They’re the difference between “process exists” and “service is functional.” Get them wrong, and your orchestrator will either route traffic to broken instances or restart healthy ones. Three Types of Probes Liveness: “Is this process stuck?” Liveness probes detect deadlocks, infinite loops, and zombie processes. If liveness fails, the container gets killed and restarted. 1 2 3 4 5 6 7 livenessProbe: httpGet: path: /healthz port: 8080 initialDelaySeconds: 30 periodSeconds: 10 failureThreshold: 3 What to check: ...

Kill -9 is violence. Your application deserves a dignified death. Graceful shutdown means finishing in-flight work before terminating. Without it, deployments cause dropped requests, broken connections, and data corruption. With it, users never notice you restarted. The Problem When a process receives SIGTERM: Kubernetes/Docker sends the signal Your app has a grace period (default 30s) After the grace period, SIGKILL terminates forcefully If your app doesn’t handle SIGTERM, in-flight requests get dropped. Database transactions abort. WebSocket connections die mid-message. ...

The Twelve-Factor App says store config in environment variables. That was good advice in 2011. For secrets in 2026, we need more. Environment variables work until they don’t: they appear in process listings, get logged accidentally, persist in shell history, and lack rotation mechanisms. For API keys and database credentials, we need purpose-built solutions. The Problems with ENV Vars for Secrets Accidental exposure: 1 2 3 4 5 # This shows up in ps output DB_PASSWORD=secret123 ./app # This gets logged by accident console.log('Starting with config:', process.env); No rotation: Changing a secret means redeploying every service that uses it. During an incident, that’s too slow. ...

Deploy on Friday. Release on Monday. That’s the power of feature flags. The traditional model couples deployment with release—code goes to production, users see it immediately. Feature flags break that coupling, letting you deploy dark code and control visibility separately from deployment. The Core Pattern A feature flag is a conditional that wraps functionality: 1 2 3 4 5 if (featureFlags.isEnabled('new-checkout-flow', { userId: user.id })) { return renderNewCheckout(); } else { return renderLegacyCheckout(); } Simple in concept. Transformative in practice. ...

When a request fails in a distributed system, the question isn’t if something went wrong—it’s where. Logs tell you what happened. Metrics tell you how often. But tracing tells you the story. The Problem with Logs and Metrics Alone You’ve got 15 microservices. A user reports slow checkout. You check the logs—thousands of entries. You check the metrics—latency is up, but which service? You’re playing detective without a map. This is where distributed tracing shines. It connects the dots across service boundaries, showing you the exact path a request takes and where time is spent. ...

Master Terraform state management with remote backends, state locking, workspace strategies, and recovery techniques for when things go wrong.

A practical guide to load balancing — algorithms, health checks, sticky sessions, and patterns for keeping your services up when traffic spikes.

A practical guide to backups and disaster recovery — automated backup strategies, testing your restores, and building systems that survive the worst.

A practical guide to caching — when to cache, what to cache, and how to avoid the gotchas that make caching the second hardest problem in computer science.

A practical guide to database migrations — tools, patterns, and strategies for evolving your schema safely in production.