Senior Frontend Developer – Generative AI (Hybrid, Vilnius)

About the role

We’re looking for an experienced Senior Front‑End Developer to join a team building production‑grade Generative AI products within a large‑scale, regulated environment. This is not a traditional front‑end role with an AI feature added on. You’ll be building the user‑facing experiences around LLMs and increasingly sophisticated AI agents, helping create products that are intuitive, responsive and trustworthy.

Key responsibilities

• Design and build responsive, accessible front‑end applications for AI‑powered products.
• Develop conversational interfaces and experiences around AI agents.
• Create UX patterns for streaming LLM responses.
• Integrate Retrieval‑Augmented Generation (RAG), tool calling and agentic workflows into user‑facing products.
• Implement source citations and transparency around AI‑generated responses.
• Build human‑in‑the‑loop controls and approval workflows.
• Design clear experiences around agent progress, uncertainty and failure states.
• Integrate front‑end applications with backend APIs, tools and ML systems.
• Collaborate closely with design, backend and data‑science teams.
• Write high‑quality production code, review pull requests and contribute to secure, compliant, accessible AI applications.
• Monitor AI workflows, including latency, token usage, tool failures and user outcomes.

Required profile

• Hands‑on experience working with agentic workflows.
• Strong commercial front‑end development experience.
• Strong product thinking and ability to simplify complex AI functionality.
• Understanding of GenAI security considerations such as prompt injection, data exposure and cost control.

Required skills

• React, Angular, Vue or similar modern front‑end framework.
• Strong TypeScript expertise.
• Experience building production‑grade Generative AI applications.
• Experience with LLM tool/function calling.
• Experience with Retrieval‑Augmented Generation (RAG).
• Experience building chat or conversational AI interfaces.
• Experience with AI evaluation, tracing, feedback loops or error analysis.
• Understanding of observability for GenAI/agentic systems.