Founding ML engineer

  • Paris
  • Full-Time
  • Start Date: 21 September 2026
  • Apply Now

About

🌍 Mission, ambition & context

The promise of AI agents is still unmet in complex, real-world business environments. Our mission is to make it possible to evaluate and train AI agents in real business settings, so they can reliably accomplish concrete, useful tasks.

Concretely, we build reinforcement learning environments that train and evaluate agents in realistic, complex contexts, think of them like video-game environments: a set of tools, a real-world dataset as a starting point, a list of tasks to accomplish, and an agent deployed to measure how well it performs them. A core part of our work is building these real-world datasets (acquisition, anonymization, enrichment).

Our goal: become the data & RL partner of choice for the labs and companies deploying agents.

Our traction speaks for itself: we've signed contracts with the two largest AI labs in the world, alongside recent partnerships with several smaller labs, all while being 100% bootstrapped. This summer, we're joining Y Combinator, which should accelerate everything.

🀝 Our values

  • Trust, the foundation of every relationship, internal and external. We extend it by default and value the ownership that comes with it.

  • Ambition, we commit, we move fast, with tenacity and efficiency.

  • Collective, team first, low ego.

  • Kindness, at the heart of every interaction.

We're building a solid, aligned, and motivated team.

Job Description

βœ… Your missions

As a Machine Learning Engineer and a founding member of the tech team, you'll play a central role in how we design, structure, and scale our products and our technical strategy. You'll report directly to Thomas (CTO & co-founder).

  • Design, build, and scale our data ingestion, transformation, and structuring processes at scale.

  • Contribute across every stage of our product:

    • the anonymization pipeline (combining algorithmic approaches with human verification) to build digital twin of companies.
    • the multi-modal data enrichment & curation pipeline
    • the reinforcement learning (RL) environments simulating real business contexts and workflows
  • Define our technical standards, take an active part in the structuring architecture decisions (tech choices, design patterns, scalability, MLOps).

  • Work closely with the product and business teams to scope and ship new data projects.

  • Mentor and grow the future members of the tech team, building a strong ML engineering & software culture at Ooak Data.

Preferred Experience

πŸ” Who we're looking for

  • 5+ years of experience in Machine Learning Engineering or software development and data architecture.

  • Strong coding experience using Python or Typescript and Rust

  • Expertise in deep learning frameworks: PyTorch, JAX, or TensorFlow.

  • Experience in Inference and RL framework: vLLM, SGLang, Slime

  • MLOps & model deployment know-how: versioning, monitoring, experiment tracking.

  • Proven track record delivering projects in an agile, collaborative environment.

  • Genuine desire to mentor and grow more junior profiles over time.

  • Demonstrated ability to thrive in a demanding, fast-growing environment.

  • Excellent analytical skills, attention to detail, and strong prioritization.

  • Fluent English, mandatory (working language with our clients and the labs).

The extras that make the difference

  • Experience with GCP (or equivalent), Modal or GPU cluster and serverless technologies

  • Experience with infrastructure as code (Terraform, CloudFormation).

  • Strong interest in data anonymization, multi-modality, and RL environments.

🎁 Why join us

  • Entrepreneurial adventure, play a key role and live the early days of an ambitious company, right at the front line of the AI revolution.

  • Backed by Y Combinator, join just as we accelerate.

  • Founding impact, shape the product, the tech stack, and the engineering culture from day one.

  • Offices in central Paris + 1–2 days WFH.

  • Package:

    • €70–90k/year depending on profile
    • BSPCE 0.2–0.5% depending on profile
    • Alan health insurance (mutuelle)
    • 50% Navigo covered

Recruitment Process

  • A 30-min intro call with GrΓ©goire (COO & co-founder)

  • A 30-min call with Thomas (CTO & co-founder)

  • A technical case study:

    • Async preparation
    • Debrief interview with Thomas
  • A final fit interview with the founding team

  • Offer

Additional Information

  • Contract Type: Full-Time
  • Start Date: 21 September 2026
  • Location: Paris
  • Occasional remote authorized
  • Salary: between 70000€ and 90000€ / year