frontend
Observability
I had long used Sentry at work, yet my personal blog had no error monitoring. This post records what I encountered while adding instrumentation with AI: failures hidden behind 200 responses, gray failure, a GA call hanging for 65 seconds, and even search data.
State Management
A practical framework for frontend state management across seven categories—Local, Global, Server, Form, URL, External State, and State Guards—with clear principles for Single Source of Truth, impossible states, State Colocation, tool selection, and modeling.
Domain Models
A frontend-focused guide to domains, domain models, and domain objects, covering Entities, Value Objects, the Anemic Domain Model, and separating ViewModels. Learn practical ways to separate domain logic in React through a comprehensive income tax example.
Reflections on Refactoring the Second Toss Frontend Fundamentals Mock Exam
A look back at refactoring the meeting room reservation app from the second Toss Frontend Fundamentals mock exam, covering monolithic component decomposition, domain logic extraction, and a test-driven refactoring process.
The AI Frontend Engineer
In an era when AI writes code for us, how can frontend engineers grow and survive? Drawing on verified sources including Karpathy’s agentic engineering, Vercel v0, the Stack Overflow Survey, and METR research, this article outlines the new skills and learning strategies centered on verification, specification, and judgment.
Abstraction
What abstraction means in frontend development and how good abstractions differ from bad ones, covering levels of abstraction, intention-revealing names, and composition from parts through the lens of React component and function design.
queryKey
An in-depth look at how TanStack Query's queryKey works and why its management evolved from inline arrays to query key factories and queryOptions. Covers the TkDodo pattern, v5 queryOptions, setQueryData, and query invalidation from a practical perspective.
Error Handling
This article explains the responsibilities of React Error Boundaries, try/catch, and TanStack Query's throwOnError, and how they work together. It distinguishes render-phase errors from asynchronous errors and covers how reset works in react-error-boundary.
Mastering React Fiber
An in-depth, React-source-based analysis of React Fiber architecture, from the Stack Reconciler to Lane priorities, double buffering, the MessageChannel scheduler, and Concurrent Features. A frequent frontend interview topic.
Can Biome Replace ESLint and Prettier?
A comparison of Biome's linting and formatting performance with ESLint and Prettier, including practical adoption experience and a migration guide for this Rust-based all-in-one toolchain.
Zustand, What Makes You ProviderLess?
A source-code analysis of how Zustand manages state without a Provider, including how its module-scoped design differs from the React Context API.