Senior Frontend Engineer

Senior Frontend Engineer at Xsolla, remote, full-time. 5+ years of experience. Work on Xsolla ID and ZK products.

Work on the frontend of the product area end-to-end: from refining tasks with product managers and designers to implementation, release, and monitoring in production. Take responsibility for technical decisions on this frontend, documenting them in writing. Take responsibility for frontend application architecture and the shared UI library/SDK used by other teams. Take responsibility for measurable frontend quality: performance, reliability, and security of user scenarios. Design and develop user scenarios: login, account management, wallet onboarding, and transaction signing. Track the behavior of these scenarios in production (errors, performance, drop-offs) and act on the results. Make and document architectural decisions for frontend applications. Develop the shared component library and frontend SDK used by other Xsolla teams. Coordinate API contracts with backend engineers, including error handling, request retries, and edge cases. Take responsibility for performance budgets: Core Web Vitals and bundle size. Improve the engineering environment: build, linters, tests, CI. Conduct code reviews. Set up and maintain AI tools in repositories (Claude Code, Codex, Cursor: rules, context, harness) so the team uses them effectively.

5+ years of commercial frontend development. TypeScript in strict mode: generics, utility types, discriminated unions, typing of module boundaries and external data. JavaScript at the platform level: event loop, asynchrony, closures, memory management. Ability to find a memory leak and explain its cause. Deep experience with React: rendering model, profiling, eliminating unnecessary re-renders. Separation of local, server, and global state and the ability to justify tool choice; understanding when SSR is justified. Semantic, responsive, cross-browser markup; modern CSS (CSS Modules, CSS-in-JS). Accessibility: ARIA, keyboard navigation, screen reader support. Performance analysis: profiling, bundle analysis, Core Web Vitals. REST API integration: error handling, retries and request cancellation, contract alignment with backend. Web security basics: XSS, CSRF, CSP, safe handling of tokens, sessions, and user data. Testing at the right level: unit, integration, E2E. Git, CI, Docker, linters, and formatters. Daily practical use of AI tools for development and review (Claude Code, Codex, Cursor), including configuring them for the repository. Reading technical documentation in English. Nice to have: Experience in domains with high security requirements: authentication and identity (OAuth2/OIDC flows on the frontend), payments, crypto wallets. Web3 frontend: wallet integration (embedded and browser), EIP-1193, EIP-6963, EIP-712; viem, wagmi, ethers.js. Next.js or Nuxt, SSR in production. Design systems and component API design, UI kits. Hybrid applications: WebView, React Native.

Full-time employment. Schedule: 5/2. Work format: remote.