AI Engineer

Responsibilities

Own Windmill's agentic coding and tool/system-building pipeline end-to-end - from the AI backend (planning, tool use, retrieval, self-correction) to the UX and developer experience that wraps it. The bar: an agent that reliably goes from a natural-language spec to a working, deployed workflow or app - and that developers actually enjoy using.

Benchmarking

• Build and maintain the eval harness, task corpus, scoring, and regression tracking. Every prompt / model / tool change is measured.

Agent loop

• Design and improve planning, tool use, self-correction, retrieval, execution feedback, multi-file editing, test-driven iteration.

Integration & DX

• Own the full surface - UI flows, editor integration, feedback loops, error states - so the experience is polished end-to-end, not just the model calls.

Prompts & models

• Systematically optimize prompts; experiment with frontier models (Claude, GPT, Gemini, open-weights); fine-tuning / RL where it pays off.

Ship to production

• Everything you build goes live and is used by thousands of developers.

Who we're looking for

• Strong CS fundamentals - algorithms, systems, distributed systems
• Solid programming skills (TypeScript, Rust a plus)
• Deep understanding of LLMs, agents, eval methodology - you've built and shipped LLM-based systems, not just played with APIs
• Rigorous, empirical mindset - you measure before you claim improvement
• 0--5 years of experience - we care more about what you've built than years on a resume

Example projects in your first 3 months

• Redesign the agent's multi-step planning so it can scaffold a full CRUD app (frontend + flow + schema) from a single prompt
• Build a live feedback UI that lets users steer the agent mid-generation - accept, reject, or redirect individual steps
• Stand up an automated eval pipeline that catches regressions before they ship and benchmarks every prompt/model change
• Add a retrieval layer that pulls relevant Windmill docs, workspace context, and past scripts into the agent's context at the right time
• Experiment with frontier models and fine-tuning to push pass rates on complex workflow generation

Offer details

Location: Paris hybrid (~3 days/week) or remote within France

Salary: €45K--€90K gross + top of market for level + 20% bonus on collective milestones

Also open to: interns / young graduates (5--6 month internship, €2,000--3,000/month, strong CDI potential)