Topic · 22 lessons in 11 series

Observability and reliability

Logs, metrics and traces, SLOs and error budgets, alerting, incidents and post-mortems: how to know what your system is doing and fix it fast.

DevOpsWhole series →

Monitoring and Logging with CloudWatchKnowing what your system is doing before your users tell you: metrics, logs, alarms and dashboards.25 min

System DesignWhole series →

Logs, Metrics & Traces: The Three Pillars“Checkout took 20 seconds and failed” — but checkout touches eleven components. How logs, metrics and traces each answer a different question, how to instrument with OpenTelemetry, and how linking them takes you from “something's wrong” to “here's why” in minutes.10 min
SLI, SLO, SLA & Error BudgetsProduct wants to ship daily; operations wants fewer changes; nobody agrees what “reliable enough” means. SLIs, SLOs and SLAs turn it into one number, and error budgets turn that number into a simple rule for when to move fast and when to slow down.10 min
Monitoring, Alerting & Blameless PostmortemsSixty alerts a week, fifty-five that don't matter — so the real one gets snoozed and customers can't pay for two hours. How to build dashboards and alerts people trust, run incidents with clear roles, and write blameless postmortems that actually make the system better.8 min

Backend in DepthWhole series →

Logging and Observability: Structured Logs, Correlation IDs, MetricsJSON logs, log levels, request IDs that follow a request through every service, and what you must never log.15 min

Scenario DebuggingWhole series →

Production Incidents: Step-by-Step GuideDetect, reduce the harm, find the cause, tell people, fix, learn. Roll back first, roles and severity, and eleven incident cases from latency that doubled overnight to a vulnerability found in production.20 min

Full-Stack QuestionsWhole series →

Deployment, CI/CD and MonitoringVercel deploys, Docker for Node, GitHub Actions, feature flags, safe rollouts and migrations, Sentry, OpenTelemetry and SLOs.43 min

Team Lead MindsetWhole series →

AI EngineeringWhole series →

Observability and Guardrails for LLM Features in ProductionWhat to log and what never to log, spans, redaction, schema validation, a circuit breaker, a kill switch, prompt versions and an incident playbook.18 min

Security for DevelopersWhole series →

Security in Practice: Code Review Checklist, Testing, Incidents and Interview AnswersA review checklist you can use tomorrow, SAST, DAST and dependency scans, what to do in the first hour of an incident, and the security questions interviewers ask with model answers.16 min

Node.js From ZeroWhole series →

Errors, Logging and Graceful ShutdownOperational versus programmer errors, uncaught exceptions, structured logs, health checks, and shutting down without dropping requests.15 min

Linux & ShellWhole series →

Disks, Memory, Logs and Troubleshooting a Slow Serverdf, du, free, load average, iostat-style tools, reading logs, and a step-by-step method for a slow or full server.15 min

Observability & SREWhole series →

More topics

Caching Security Authentication and authorization Performance Databases and SQL Testing Networking and HTTP Docker and Kubernetes API design Scalability and distributed systems Async and concurrency AI and LLM apps Deployment and CI/CD Architecture and design patterns React and Next.js