Lead Software Engineer, AI SaaS Platform (Full-Stack & ML)

We are hiring one Tech Lead to own our AI SaaS platform end to end, from a high-traffic, secure product surface down to the NLP models and data pipelines that power it.

You will lead a cross-functional team (fewer than 10 engineers and ML/Data engineers), set technical direction across full-stack and ML, and stay close enough to the code to ship. You will work daily with scientists, biologists, product, and regulatory.

This is not two jobs bolted together: the best AI products come from one person who can reason from the user-facing feature down to the model that powers it.

What You'll Own

Platform & Product (Full-Stack SaaS)

• Ship scalable, maintainable features across the stack (React, Node.js, Python).
• Architect for high traffic, speed, and scalability, with security and compliance built in by design.
• Stay product-oriented: ship valuable features fast to hit short time-to-market.

AI / ML & Data

• Train and improve NLP models: classification, named entity recognition (NER), relation and text extraction, entity linking, standardization, aggregation.
• Own the full NLP/ML lifecycle: training, evaluation, deployment, monitoring.
• Run MLOps with tools like MLflow, Langfuse, and LiteLLM (experiment tracking, observability, cost control, validation automation), and integrate LLM APIs into production.

Pipelines & Reliability (SRE / DevOps)

• Own the data pipelines behind delivery, handling hundreds of daily workflows over millions of biomedical documents.
• Ensure high availability and performance in production, and drive data quality and compliance to strict medical standards.

Leadership

• Manage, mentor, and grow the team; deliver solutions aligned with business goals.
• Communicate clearly with technical and non-technical stakeholders (CTO, product, regulatory, customers).

What Success Looks Like

In your first year: platform and pipelines mapped and shipping faster, a clean MLOps loop in place (tracking, observability, evaluation), measurable gains in model quality and delivery speed, a grown team, and benefit-risk analysis moving toward real-time. We value judgment over heroics: what to ship now, what to defer, what to cut.

Do you have experience in Terraform?, Do you have a Master's degree?, We want a strong full-stack SaaS engineer with a real ML track record, not five specialists in one. Full-stack depth and hands-on NLP are the non-negotiable core; the rest is learnable on the job.

• Degree in Computer Science / Engineering or equivalent, with 8+ years in software engineering including high-traffic SaaS platforms.
• Strong full-stack experience: a modern front-end (React preferred, Vue or Angular accepted) plus Node.js and Python backends.
• 3+ years of professional Python.
• A genuine AI/ML track record: you have personally trained and shipped NLP models (NER, extraction, classification, standardization), not just consumed APIs.
• Hands-on MLOps: experiment tracking and LLM observability (MLflow, Langfuse, LiteLLM, or equivalents).
• REST, NoSQL, DevOps fundamentals, cloud (AWS, GCP, or Scaleway), and containerization (Docker, Kubernetes).
• Git, plus a real understanding of accessibility and security/compliance.
• Product orientation: a demonstrated ability to ship the right thing fast.
• Excellent English (French a plus) and proven team leadership.

Strong Pluses

• Our data stack: FastAPI, SpaCy, Spark NLP, Airflow, S3, PostgreSQL, Elasticsearch, Qdrant.
• IaC and CI/CD: GitLab CI, Terraform, Ansible, AWS EKS.
• Regulated/high-compliance experience (medical, pharma, fintech), Agile and TDD, vector search/RAG and LLM extraction pipelines.

• A multicultural team of engineers, scientists, and biologists, and a broad mandate: own product and ML, not a narrow slice.
• Hybrid flexibility (2-3 days remote/week) from Future4Care in Paris 13e.
• Package: 70K-80K€ gross/year, plus 13th month, performance bonuses, RTT, daily transport coverage, work-from-home allowance.
• Onboarding and training in Pharmaceutical Sciences or AI, tailored to your background.

ArcaScience is a leading French AI startup using biomedical data to predict a drug's risk and efficacy before it reaches the patient, then re-evaluate that risk once patients are taking it. Our impact is concrete: accelerating drug development and helping patients get the right drug. We run our own AI models that analyze the benefit-risk profile of molecules for specific pathologies and patient groups, and tomorrow, individual patients. We are significantly accelerating our three-year growth and global expansion from the Future4Care healthtech hub.