React Concurrency, Forms & Performance

Transitions, deferred rendering, React 19 Actions, optimistic UI, external stores, profiling, code splitting, and large-list behavior.

10 drillsPractice one at a timeOrdered pathArchitecture scenarioDebugging scenarioConcept questionComparison question

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React memoization judgment

Treats memoization as measured performance work and accounts for prop identity, context, readability, and React Compiler.

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