Practical frontend engineering guides for React, Next.js, TypeScript, and web performance.
18 items under this tag.
Understand how React's event system really works: SyntheticEvent wrapping, root-level delegation, Fiber-based listener collection, dispatch queues, and plugin-based event extraction.
Understand how React time slicing really works: Fiber turns rendering into units of work, the Scheduler decides when to yield, and work-in-progress state lets React resume or restart renders.
Understand how React batches useState updates: dispatchSetState creates update records, root scheduling reuses the same render task, and updateReducer processes the queue into one final state.
Understand how React turns setState into a DOM update through batching, scheduling, the render phase, the commit phase, and effect timing.
Learn when setState appears synchronous or asynchronous in React, why the answer changes across calling contexts, and how React 18 automatic batching changes the behavior.
Understand how Fiber, scheduling/time slicing, lanes, and double buffering work together to make concurrent rendering responsive and consistent.
Understand how React Fiber stores both hooks in the same effect list, why HookLayout and HookPassive tags matter, and when each runs during the commit phase.
Understand the real difference between useState and useReducer in React, why useState is basically a special case of useReducer, and when each Hook is the better fit.
React Hooks rely on call order, not variable names. Learn how Fiber stores hooks in a linked list and why changing the call order breaks state alignment.