React
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.
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.
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.
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.