Sébastien Retoux

Senior Tech Lead — Backend & Data Expert

About

I specialize in building robust backend APIs that scale gracefully and remain maintainable over time.
My experience covers the full lifecycle of backend systems: from designing clean service boundaries and resilient contracts, to implementing secure, high-performance endpoints that serve millions of requests reliably.

Beyond APIs, I work extensively with data pipelines, particularly using Apache Airflow to orchestrate complex workflows and ensure data quality, lineage, and timely delivery.

I have hands-on knowledge of a broad set of AWS services — EC2, ECS, CloudFront, S3, RDS, Lambda, among others — and know how to combine them into architectures that balance cost, resilience, and speed of delivery.

As a technical lead, I guide teams in making pragmatic architectural choices, fostering best practices, and building a culture of learning and ownership. I enjoy helping engineers grow, while keeping delivery aligned with business goals.

Security is a constant focus in my work: from applying least-privilege principles and hardening infrastructure, to integrating authentication and authorization patterns directly into system design.

I also keep a close eye on artificial intelligence, from leveraging existing APIs and cloud services to experimenting with integrating AI-driven features into backend systems and data workflows.