Full-Stack Engineer

Our company

Colette ( and ) is on a mission to help people age well and make cities more livable. We do this through two complementary products: an intergenerational house-sharing service that matches students and young professionals with seniors who have a spare room, and a club of online and offline activities dedicated to seniors.

In May 2025, Colette was acquired by Renée Costes, France’s leading specialist in senior living (including viager - life annuity real estate). The partnership accelerates our mission and gives us the scale to reach millions of seniors across France.

Why this matters: by 2035, roughly one French person in three around 22 million people will be over 60 ( INSEE ), and 90% of them want to age at home . Loneliness has the same negative health impact as smoking 15 cigarettes a day, and housing affordability has become a crisis for young people in big cities (61% of 1834-year-olds report struggling to find housing ). Bringing generations together solves both problems at once. And on the activities side, keeping seniors physically and mentally active is one of the most reliable ways to preserve their health, independence, and joy which is exactly what our club is designed to do.

Where we stand today

• We know how to attract and retain hosts willing to rent their spare rooms on Colette.
• We consistently meet the demand of young people looking for housing.
• Our matching process is proven, and active members rate our house-sharing service 4.5/5.
• We know how to build and retain a club of activities that seniors love.

Where we’re going

• Build and grow a trusted community, online and offline.
• Deliver a world-class intergenerational house-sharing experience in France.
• Increase the number of house-sharing matches we create each month.
• Become the largest club of activities dedicated to seniors.

To get there, we’re looking for an outstanding engineer, as keen and enthusiastic as we are, to help us build the product and technology that makes it possible.

Our stack

• Backend: Elixir (Phoenix), Ruby
• Frontend: React with Next.js and Remix, TypeScript
• Mobile: Flutter
• APIs: GraphQL and REST
• Data & payments: PostgreSQL, Stripe
• Infra & delivery: Docker, Fly.io , Neon, AWS, Google Cloud, GitHub

AI: frontier models from Anthropic, OpenAI, and Google; Claude as everyday collaborator, plus AI-powered features in the product