AI engineer

Lucis
Paris, France
3 days ago

Role details

Contract type
Permanent contract
Employment type
Full-time (> 32 hours)
Working hours
Regular working hours
Languages
English
Experience level
Senior

Job location

Paris, France

Tech stack

Artificial Intelligence
Amazon Web Services (AWS)
Clinical Data Repository
Encodings
Cursor (Graphical User Interface Elements)
Github
Python
PostgreSQL
Large Language Models
Pubmed
Machine Learning Operations
Virtual Agents
Terraform
Data Pipelines

Job description

We're building AI agents that act as a doctor for preventive health - analyzing 110+ biomarkers, reasoning over clinical data, and delivering protocols that change how people age. The system works. Now we need to make it smarter, faster, and ready for millions of users.

As our AI Engineer, you own the reasoning engine: the agents, the retrieval pipelines, the clinical workflows, and the infrastructure that makes it all reliable in production. You work directly with our medical team to translate clinical knowledge into systems that actually behave like they understand it.

This isn't a research role. It's a build role. The gap between a great LLM demo and a trustworthy AI doctor is enormous - your job is to close it.

You could be responsible for

  • AI agent architecture - design and ship the multi-agent system behind our AI doctor: reasoning, planning, tool use, clinical citation, and safe fallback behavior
  • Retrieval & knowledge - vector infrastructure, embedding pipelines, RAG architecture over clinical literature and user health data. You know the difference between retrieval that works and retrieval that a clinician would trust
  • Data pipelines - ingestion and normalization from labs (Eurofins, Randox), wearables, and third-party partners. Clean data in, reliable inference out
  • Production reliability - LLM endpoints that reason correctly at scale, with observability, evals, and failure modes you've thought through before they happen
  • Medical collaboration - translate complex clinical requirements into agent workflows, working side by side with our medical advisors. You don't need to be a doctor, but you need to earn their trust, Python repo and TS monorepo (platform) · PostgreSQL + Prisma · AWS (Terraform) · GitHub Actions · Claude Code + Cursor · AI/agent framework: mostly Langchain ecosystem

Requirements

You're passionate about the future of human health and want your work to help people stay healthy for longer. You move quickly from idea to execution, take full ownership of what you build, and work best with talented people who care as much as you do.

You thrive in fast-moving environments, learn by doing, and value feedback as a way to continuously improve.

You'll fit in well if

  • You have 8+ years' experience building and shipping software and ML systems in production
  • You've shipped AI agents in production recently - not as a side project, as the core product
  • You think in systems: prompts, retrieval, tool orchestration, evals, and failure modes are all part of the same design problem
  • You're hands-on with vector databases, retrieval pipelines, and LLM endpoints - Python-native, comfortable in LangChain or equivalent
  • You write evals before you ship, because you know that vibes-based QA doesn't work for clinical reasoning
  • You've worked with messy real-world data (health, finance, legal) and built pipelines that handle it without breaking silently
  • You're genuinely obsessed with health - you track your own biomarkers, read PubMed, or are just deeply frustrated that healthcare is still reactive

We might not be a fit if

  • You need a clearly defined role with stable responsibilities.
  • You prefer strategic advisory work over hands-on execution.
  • You've only worked in large, well-established companies.
  • You need perfect information before making decisions.
  • You prioritise predictable 9-5 work over mission intensity.
  • You're uncomfortable with frequent context-switching and urgent pivots.

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