Knowledge Index — 지식 지도

As a single model grows complex, reads and writes start tripping each other up. Here's how CQRS solves that problem — from simple separation to full event sourcing, with TypeScript examples throughout.

I was running a service with zero insight into user behavior. Setting up PostHog changed how I make product decisions—from guessing to knowing.

Why does 'tech debt' make non-developer managers glaze over? Learn how to translate technical debt into business language, frame refactoring as investment, present to stakeholders with real metrics, and use prioritization frameworks that actually get buy-in.

Managing payment flow state with if-statements and boolean flags led to bug hell. XState's state machines made impossible states truly impossible.

Explore how Zod schema validation and tRPC solve the pain of REST APIs with manual types. Covers router setup, client-side type inference, error handling with Zod, migrating from REST, and when tRPC is and isn't the right tool.

I needed to send signup confirmation emails but HTML email development is hell. React Email lets you build emails like components, and Resend handles delivery.

I couldn't understand my own API after 3 months. Practical REST API design patterns for naming, versioning, pagination, and error handling.

Explore why synchronous request-response communication breaks down in microservices and how Event-Driven Architecture solves it. Covers Kafka vs RabbitMQ vs SQS, domain events vs integration events, event sourcing basics, eventual consistency, and practical Node.js examples.

Hexagonal Architecture isolates your business logic from the outside world using Ports and Adapters. Learn how to invert dependency direction so your core domain stays untouched regardless of what database, framework, or external service you swap in — with TypeScript examples throughout.

Every REST API I built had type mismatches between frontend and backend. tRPC eliminated the gap entirely—no API specs, no codegen, just types that flow.

Applying Uncle Bob's Clean Architecture directly to frontend creates unnecessary complexity. Here's a practical, frontend-adapted layering strategy that actually works in production.

I tried navigating my own service with just a keyboard and tab focus jumped everywhere. What I learned fixing accessibility issues in practice.

100% code coverage but bugs still slip through? Having tests doesn't mean having good tests. Here's how mutation testing reveals the real quality of your test suite.

Adding English to a Korean-only blog with next-intl. Lessons from implementing i18n in Next.js App Router, including routing, message files, and Server Components.

TDD and BDD both share a 'tests first' philosophy but differ in focus and application. From the Red-Green-Refactor cycle to Gherkin syntax — a practical TypeScript comparison.

I built a service and nobody came. How I implemented technical SEO in Next.js to drive organic traffic without a marketing budget.

That fear when you get your first code review? Everyone goes through it. A practical guide covering everything from writing review-friendly PRs to giving constructive feedback and building a healthy review culture.

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've wasted hours with direct fetch mocks or vi.mock() on axios, only to find the mock drifted from the real API. MSW intercepts at the network level and eliminates that problem. Here's everything from setup to Vitest and Storybook integration.