Senior Frontend Engineer - React Specialist (MUI, Redux, IndexedDB)

About the Role

We're seeking an elite frontend architect to lead the development of scalable, offline-first SPAs. You'll design performant, accessible UIs using React, MUI, Redux, and IndexedDB, ensuring WCAG compliance and sub-100ms interactions. If you can expertly answer 107 advanced technical questions on semantic HTML/CSS in React-MUI integrations, ES6+ JS nuances, Fiber internals, state orchestration, and perf optimizations (spanning landmarks, ARIA, custom props, event loops, hooks, reducers, virtual scrolling, SSR, and more), this is your challenge.

Key Responsibilities

• Architect deeply nested MUI components with Redux-driven state and IndexedDB persistence for offline navigation, forms, and dashboards.
• Optimize responsive layouts, animations, and virtual lists using CSS Grid/Flexbox, media queries, and react-window for terabyte-scale data.
• Implement immutable state patterns, RTK Query endpoints, and optimistic updates with Zod validation and error boundaries.
• Profile and audit Core Web Vitals (LCP/CLS/FID) via Lighthouse, minimizing reflows/repaints with transforms, batching, and tree-shaking.
• Ensure semantic HTML, ARIA live regions, and custom hooks for polymorphic UIs, with SSR hydration via Next.js and Emotion.

Required Experience & Capabilities

• 10+ years in frontend engineering

  , with 5+ years mastering React 18+ ecosystems (MUI 5+, Redux Toolkit, IndexedDB/IDB APIs).

• Proven expertise in advanced topics

  :
• Semantic HTML/CSS: Landmarks, custom data attrs, validation, CSS vars scoping, pseudo-elements, containment, specificity cascades, subgrid/masonry.
• ES6+ JS: Strict mode, TDZ, event phases, event loop/macrotasks, Promises/async/await, tagged literals, WeakMap/Set, V8 GC/heap profiling.
• React Advanced: Fiber reconciler, hooks (useMemo/Callback/Transition/DeferredValue), controlled/uncontrolled inputs, HOCs, Context/Providers, lazy/Suspense, forwardRef, exhaustive deps.
• State Management: Redux reducers/thunks/sagas, RTK Query, normalization, middleware for IndexedDB sync, vs. MobX/Zustand/Recoil.
• Performance: Virtual DOM diffing, code-splitting (Vite/Webpack), memoization pitfalls, SSR/CSR hybrids, bundle analysis, idle callbacks.

• Tools/Practices

  : ESLint/TS configs, Zod/Formik/react-hook-form, React Router v7, Next.js app router, Module Federation, Chrome DevTools profiling.

• Soft Skills

  : Ability to dissect and solve complex issues (e.g., FOUC avoidance, race conditions, memory leaks) in monorepos/micro-frontends; mentor juniors on best practices.