FOUNDING ML ENGINEER

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

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

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 Grégoire (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