Senior Frontend Engineer

About the role

We are seeking a Senior Frontend Engineer to shape the UI of our AI agent platform. You will work on complex, collaborative interfaces and own the backend‑for‑frontend (BFF) layer that connects many micro‑services.

Key responsibilities

• Build and evolve React interfaces for conversation tools, graph‑based flow builders, agent configuration, testing consoles and analytics dashboards.
• Own and develop the NestJS BFF, aggregating REST micro‑services, handling authentication, pagination, streaming and error contracts.
• Drive consistency of the component ecosystem: migrate legacy Ant Design components to a Mantine‑based design system, maintain the shared UI library and Storybook.
• Ensure product quality with Vitest unit/component tests and Playwright end‑to‑end tests, covering critical user flows and SDK functionality.
• Collaborate with API, SDK, QA and documentation teams on contracts, code reviews, bug fixes and test scenarios.
• Partner with the documentation team to produce integration guides and practical code examples.

Required profile

• 6+ years of professional frontend/full‑stack product development, including 5+ years of production React.
• Senior‑level expertise in TypeScript (strict mode, React 19) and modern tooling such as Vite and monorepos.
• 2+ years of Node.js experience, preferably with NestJS, and solid understanding of BFF patterns.
• Production experience in micro‑service environments (10+ services) and ability to define BFF boundaries.
• Experience building complex, stateful UIs (graph/canvas editors, collaborative tools) with undo/redo, optimistic updates and conflict handling.
• Strong frontend architecture skills (FSD, modular/layered) and ability to work within an existing team architecture.
• Product sense and autonomy to make UI/UX decisions using a design system.
• Hands‑on testing culture with Vitest and Playwright.
• Familiarity with modern data tools (React Query, Socket.io, Prisma, PostgreSQL) and AI‑assisted coding tools (Claude Code, Cursor, Codex, GitHub Copilot).

Required skills

• React, TypeScript, Vite, monorepos
• Node.js, NestJS, BFF, OpenAPI
• PostgreSQL, Redis
• Ant Design, Mantine, Storybook
• Vitest, Playwright
• React Query, Socket.io, Prisma
• Yjs, Automerge, WebRTC, SIP
• Kubernetes, Helm, OpenTelemetry, Prometheus
• Claude Code, Cursor, Codex, GitHub Copilot

What we offer

• Award‑winning AI products used by large tech corporations.
• Cutting‑edge stack: speech tech, NLP, generative AI, voice‑first agentic architecture.
• High engineering bar with real ownership and visible impact.
• Fast career progression in a senior‑heavy team.
• Startup pace with enterprise stability and real revenue.
• Fully remote work across Europe.
• 21 vacation days + public holidays + 5 sick days.
• Private English lessons via Preply.