Knowledge Index — 지식 지도

Separating deployment from release means you can roll back anything, anytime. A comparison of LaunchDarkly and Unleash, how to integrate their SDKs in React/Next.js, and how to keep flag debt under control.

Why clicking through the AWS console is a recipe for pain, and how declaring infrastructure as code with Terraform changes everything. Practical VPC + EC2 + RDS example included.

My service was down for 12 hours and I had no idea. How I built a minimal monitoring stack as a solo developer with free and low-cost tools.

I was tired of users reporting errors before I knew about them. How I set up Sentry in a Next.js project for real-time error tracking and alerting.

I tried to save money by deploying to AWS S3 instead of Vercel, but ended up with a broken site. I share the three nightmares of Static Export (Image Optimization, API Routes, Dynamic Routing) and how to fix them.

Postmortem purpose and writing method

Running a service means failures will happen. Reading Google's SRE book made me realize that operations is a high-level engineering problem, not just toil. I walk through how the concepts of SLI, SLO, and Error Budget shift your mindset from firefighter to architect.

Passing functional tests doesn't mean your server can handle real traffic. '100 tests by one person' and '1 test by 100 people simultaneously' are completely different problems. Here's how to get started with k6 load testing, find bottlenecks, and fix them.

I adopted Kubernetes (k8s) blindly because it was 'trendy' and 'scalable'. The result? A massive infrastructure bill and YAML hell. I share my honest retrospective on the dangers of over-engineering and when you should actually use Kubernetes.

Managing infrastructure manually via a web console is a disaster waiting to happen. I share my horror story of accidentally terminating a production database server and how Infrastructure as Code (IaC) with Terraform saves us from human error, providing version control, reproducibility, and peace of mind.

Stop fearing Friday deploys. Feature Flags (or Toggles) allow you to push code to production while keeping it dormant. We explore the 4 categories of flags, how they enable Trunk-Based Development, the power of Canary Releases, and the critical importance of cleaning up stale flags to prevent technical debt.

Hardcoding secrets is a recipe for disaster. We explore the 12-Factor App methodology's take on configuration. From .env files in local dev to AWS Secrets Manager in production, learn how to manage environment variables securely across CI/CD pipelines and containerized orchestration systems.

Users complained the service was slow, but I was blindly grepping log files. I share how I moved from 'driving blind' to full observability using Prometheus and Grafana, and explain Google's 4 Golden Signals of monitoring.

Understanding Terraform principles and practical applications through project experience

Solving server waste at dawn and crashes at lunch. Understanding Auto Scaling vs Serverless through 'Taxi Dispatch' and 'Pizza Delivery' analogies. Plus, cost-saving tips using Spot Instances.

Hardware vs OS Virtualization. A deep dive into Hypervisors (Xen, KVM) vs Containers (LXC, Docker). Includes Glossary, FAQ, and Cost Analysis.

The ultimate guide for Engineers. Includes Architecture Deep Dive, 20-term Glossary, 10-item FAQ, and detailed Security Hardening checklists.

Logs are the black box of your infrastructure. When disaster strikes, grep is not enough. We explore the ELK Stack—the industry standard for centralized logging. Understand the roles of Elasticsearch, Logstash, and Kibana, compare modern alternatives like Fluentd and Vector, and learn strategies for Index Lifecycle Management (ILM).

Stop hiring 'DevOps Engineers' to fix your broken culture. DevOps is about breaking down silos between Development and Operations, not creating a new silo. We explore the 'Three Ways' of DevOps (Flow, Feedback, Learning), the importance of CI/CD, Immutable Infrastructure, and why DevSecOps is the inevitable future.

Why would Netflix intentionally shut down its own production servers? Explore the philosophy of Chaos Engineering, the Simian Army, and detailed strategies like GameDays and Automating Chaos to build resilient distributed systems.