Senior Software Engineer

We are Ooak Data. The promise of AI agents is still unmet in complex, real-world business environments. Our mission is to make it possible for agents to reliably accomplish concrete and useful tasks. That is why we are building Alexandria, the world's largest library of real-world business workflow datasets. Over the next 6 months, we will acquire and anonymize 300+ full data ecosystems from real-world companies. This will allow us to become the leader of real business workflow data and be in the best position to launch our own data research lab in early 2027, enabling new services that help companies around the world automate their workflows with AI. This summer we need to build our elite squad to move extremely fast and confirm our leading position on company data. Our values are trust, the foundation of every relationship, internal and external, which we extend by default while valuing the ownership that comes with it. We value ambition, committing, moving fast, with tenacity and efficiency. We are collective, team first, and low ego. We prioritize kindness at the heart of every interaction. We are building a solid, aligned, and motivated team. The job offer is based in Paris (city center), on-site with 1 to 2 days WFH. The start date is as soon as you are available. The contract is full-time (CDI), and we are open to freelancing for the summer. The team consists of 3 co-founders (Pierre-Louis, CEO; Grégoire, CPO & COO; Thomas, CTO) and 3 FTEs (1 ML engineer and 2 ops). Your missions as a Software Engineer and a founding member of the tech team, you will play a central role in how we design, build, and scale the platform that powers our datasets and RL environments. You will report directly to Thomas (CTO & co-founder). - Design, build, and scale the web platform and internal tooling our team and partners use to ingest, process, and explore data. - Build robust back-end services and APIs powering our data pipelines and RL environments. - Craft clean, reactive front-end interfaces for data curation, annotation, and monitoring. - Define our technical standards and take an active part in the structuring architecture decisions (tech choices, design patterns, scalability, DevOps). - Work closely with the product and ML teams to scope and ship new features end to end. - Mentor and grow the future members of the tech team, building a strong software engineering culture at Ooak Data. Who we are looking for: - 5+ years of experience in software engineering, ideally full-stack or back-end focused. - Strong coding experience in TypeScript and Python, with a plus for Rust. - Solid experience with modern web frameworks (React, SvelteKit, or equivalent) and Node.js. - Comfortable designing and operating APIs, relational databases (PostgreSQL), and micro-services. - 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 include experience with GCP (or equivalent), Docker, and serverless technologies, experience with infrastructure as code (Terraform, CloudFormation), and a strong interest in data engineering, anonymization, and AI/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 company and its culture from day one. - Offices in central Paris + 1 to 2 days WFH. - Perks: Alan health insurance (mutuelle), unlimited GPT & Claude tokens, 50% Navigo covered. Recruitment process: We can move very fast. A 30 min intro call with Grégoire (COO & co-founder). A 30 min call with Thomas (CTO & co-founder). A technical case study including async preparation and a debrief interview with Thomas. A final fit interview with the founding team.