Senior Frontend Engineer

This is a fully remote position, open to applicants in Serbia.

📋 Description

• Develop and enhance React interfaces for an AI agent platform, which includes tools for conversation and prompt engineering, graph-based collaborative flow builders, agent configuration and testing interfaces, as well as call analytics dashboards.

• Create interfaces according to Figma designs.

• Take ownership of and advance the NestJS BFF layer.

• Aggregate REST microservices utilizing typed clients generated from OpenAPI.

• Manage authentication, pagination, streaming, and error contracts to maintain a streamlined frontend layer.

• Contribute to backend development with PostgreSQL and Redis.

• Evolve and sustain the frontend component ecosystem.

• Transform legacy Ant Design components into a Mantine-based design system.

• Lead the shared UI library and Storybook.

• Ensure consistency across various product applications.

• Guarantee product quality through Vitest unit/component tests and Playwright end-to-end and critical user-flow testing, including SDK functionality.

• Collaborate with cross-functional teams and product v-teams on API contracts, SDK protocols, code reviews, bug fixes, QA support, and testing scenarios.

• Participate in initiatives that require frontend or platform expertise.

• Work alongside the documentation team to produce and sustain integration guides and practical code examples.

⛳️ Requirements

• Over 6 years of professional experience in frontend/full-stack product development.

• More than 5 years of React experience in production environments.

• In-depth senior-level TypeScript proficiency, including strict mode, React 19, Vite, and monorepos.

• At least 2 years of Node.js development experience on the server side.

• Practical experience in building and maintaining BFF or API gateway layers.

• Knowledge of service aggregation, authentication, pagination, error contracts, and clear BFF boundaries.

• Extensive production experience in microservice environments, ideally with more than 10 services.

• Experience in developing complex, stateful UIs such as graph/canvas editors or collaborative interfaces.

• Familiarity with undo/redo functions, optimistic updates, conflict resolution, and complex state management.

• Strong skills in frontend architecture and code organization, including FSD or modular/layered architectures.

• Ability to collaborate effectively within an established team architecture.

• Strong product sense and independence in UI and UX decision-making.

• Practical experience in writing and maintaining unit/component tests with Vitest.

• Practical experience in conducting end-to-end tests using Playwright.

• Hands-on experience with React Query, Socket.io, Prisma, and PostgreSQL.

• Experience with AI-assisted development tools like Claude Code, Cursor, Codex, GitHub Copilot, or similar.

• Understanding of the value AI agents provide and the necessity for human oversight.

• Experience with agent instructions and automated reviews integrated into repositories/CI.

• Proficiency in English language skills, as indicated by the benefit of private English lessons.

🏝️ Benefits

• Fully remote work opportunity within Europe.

• 21 vacation days in addition to public holidays and 5 sick days.

• Access to private English lessons through Preply.

• Chance to work on award-winning AI products for technology corporations.

• Access to a cutting-edge technology stack, including Speech Technologies, NLP, Generative AI (LLMs, diffusion models), and voice-first agentic architecture with a focus on privacy and on-premises deployment.

• High engineering standards and genuine ownership of projects.

• Rapid career advancement opportunities.

• Dynamic startup environment combined with the stability of enterprise-level clients and real revenue.