Mid Level Full Stack Engineer (Fast growing startup)

Join Stairpay, a fast-growing startup revolutionizing the affordable housing sector. As a Mid Level Full Stack Engineer, you'll work on a platform that automates and streamlines the purchasing journey, enhances resident experience, and provides financial solutions for institutional landlords. You'll own features end-to-end, collaborate with clients, and shape the product. Enjoy a range of benefits, including remote work options, generous stock options, and a gym in the office.

Missions

• Concevoir, concevoir, mettre en œuvre, déployer et itérer sur des fonctionnalités de bout en bout.
• Diriger l'outil, pas seulement le clavier - orchestrer les agents d'IA à travers la mise en œuvre, la révision et la vérification.
• Travailler directement avec les clients - participer aux appels avec les associations de logement, observer les utilisateurs réels.

Profil recherché

• AI raises the floor. We raise the ceiling - that's our engineering vision. The floor is everything that happens without a person doing it by hand: implementing, verifying, reviewing, deploying, correcting, rolling back, around the clock. The ceiling is what's possible, and raising it is our responsibility
• You're the director, not a rubber stamp - this isn't a job where you type code all day, and it isn't a job where you wave through whatever a model produced. You decide what gets built and why, you direct the tooling that builds it, and you own whether it's right
• Full-stack, shipped in production - you've taken complete features across frontend, backend and database into the hands of real users, and stayed to fix what broke
• Strong TypeScript - comfortable with advanced patterns; you write type-safe code because it makes the system easier for the next person (and the next agent) to change safely
• Modern React & Next.js - you understand rendering strategies, data fetching and state management, and know when each is the right call
• Databases & APIs - SQL schema design, query optimisation, sensible API design. You can spot an N+1 and know what to do about it
• Cloud-native - you've deployed and operated on AWS (or GCP/Azure), and you're comfortable with managed services and serverless
• You work with AI, and you verify it - you direct agents on real work rather than autocompleting, and more importantly you catch where they're subtly wrong. Knowing where you don't trust it is the skill we're hiring for. You don't need to have built agent tooling before - you need to want to
• You want to build the tooling, not just use it - how software gets built is being reinvented right now, and there's no playbook for it. We're designing the AI infrastructure this company runs on, and we want someone who'd rather invent our version of it than wait for someone else's
• Product-first - you ask "why are we building this?" before "what should we build it with"

Nice to have:

• Accountable - you take responsibility for outcomes, follow through on what you commit to, and proactively unblock yourself. You'll be joining a small team who are keenly motivated to improve our systems and our output every day
• Testing and observability as instinct - meaningful tests, visible failure paths. On our platform the tests aren't a chore; they're what lets a change ship without a human watching it
• Autonomous collaboration - you work independently, seek input on the big calls, and help teammates who are stuck
• Client-facing confidence - you can explain a technical decision to a housing association operations lead and enjoy doing it
• Fintech or property domain exposure - useful, not required. What matters is caring that the money maths is exactly right