Initializing Systems...
System 3 · React
Expert command. Performance optimization, advanced state architecture, testing, and design patterns that separate engineers from commanders.
useMemo & useCallback
Memoization is the cloaking device against unnecessary re-renders. Learn when useMemo and useCallback deliver real gains vs. premature optimization.
React.memo — Component Shield
Wrap components with React.memo to skip re-renders when props haven't changed. Learn the shallow comparison rules and when memo doesn't help.
Code Splitting — Warp Jump
Split your bundle with React.lazy and Suspense. Measure bundle size impact and implement route-based code splitting.
Performance Debrief
Review performance optimization patterns and when to apply them.
useReducer — Command Protocol
useReducer models state as explicit actions and transitions — essential for complex state with multiple sub-values or intricate update logic.
Complex State Patterns
Model a multi-step form, a shopping cart, and a finite state machine with useReducer and immer for immutable updates.
Zustand — Fleet State Grid
Graduate to Zustand for global state management. Build a mission store with slices, selectors, and async actions.
State Armory Debrief
Consolidate your state architecture knowledge.
React Testing Library — Simulation Bay
Test components the way users use them — by querying the DOM as a human would, not by reaching into internal implementation.
Testing User Interactions
Use userEvent to simulate realistic clicks, typing, and form submissions. Assert on UI outcomes, not implementation details.
Async Testing & Mocking
Test async operations, mock fetch calls with msw, and handle loading/error states in tests.
Testing Chamber Debrief
Review testing strategies and coverage goals.
Compound Components
Build flexible component APIs using the compound component pattern — components that share implicit state without explicit prop threading.
Render Props & HOCs
Study historical patterns — render props and higher-order components — and understand how hooks replaced them.
Mastery Strike — Full Feature Build
Build a complete React feature from scratch: compound component API, custom hooks for logic, Zustand for state, tests for confidence.
Andromeda Nexus — Final Debrief
You've mastered React. Rank: Navigator. The fleet awaits your command.
Architect a full dashboard with Zustand state management, React Query for data fetching, performance optimizations, and a full test suite.