React
overlay-kit
Swapping a global isOpen flag for one await: what I gained, what I lost, and how overlay-kit's events, reducer, and openAsync core really work.
Kalyx
Why I built Kalyx, a headless React DatePicker, and how it differs from Ark UI, React Aria and react-day-picker: UTC ISO values, Intl DST, timezone tests.
State Management
A framework for frontend state management across seven categories (local, global, server, form, URL, external, guards) with React modeling criteria.
Reflections on Refactoring the Second Toss Frontend Fundamentals Mock Exam
Refactoring the meeting room reservation app from the second Toss Frontend Fundamentals mock exam: component decomposition and domain logic extraction.
queryKey
How queryKey works in TanStack Query and why it evolved from inline arrays to query key factories and queryOptions, with the TkDodo pattern.
Placing ErrorBoundary
How many ErrorBoundary layers to use, how much screen one failure costs, and what else a retry button has to unlock before it actually retries.
Error Propagation
Throw the same error from seven places and only four reach an ErrorBoundary. This post traces where each kind actually propagates.
Mastering React Fiber
A source-based analysis of React Fiber: Stack Reconciler, Lane priorities, double buffering, the MessageChannel scheduler, and Concurrent Features.
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.