Senior Frontend Developer Warsaw Kozak Agency $$$
Madfish
Software Engineering
Europe
Posted on May 10, 2026
Location: Warsaw!
Start: as soon as possible
Duration: long-term
Languages: Polish is mandatory !!, English: B2
Hybrid: 1-2x week in Warsaw | 4+ years React exp | English B2+
- Core Stack: Expert-level React 19+ (Hooks, Suspense, RSC) and TypeScript (Strict Mode, Utility Types, Generics).
- Architecture: Next.js (Web) and Turborepo/Nx for unified monorepo management across platforms.
- State & Forms: XState/TanStack Query (no Redux), Zod, React Hook Form, and nuqs for type-safe params.
- Styling & UI: Tailwind CSS v4+ and NativeWind for cross-platform component consistency.
- Performance Engineering: Expert profiling of Core Web Vitals (LCP, INP, CLS) and React Native bridge/memory optimization.
- Quality Assurance: Vitest, React Testing Library, and Playwright with a focus on 80%+ critical path coverage.
- BFF & API: Next.js API routes and oRPC for end-to-end type safety.
- AI & Security: Designing agentic workflows for dev-velocity; expert OWASP Top 10 mitigation and dependency auditing.