Senior Fullstack Engineer (AI)

TL;DR

Senior Fullstack Engineer (AI/Fullstack): Building AI-powered features for a sustainability data intelligence platform with an accent on end-to-end feature ownership and scalable backend systems. Focus on designing robust data models, implementing GraphQL APIs, and optimizing frontend interfaces to make sustainability data actionable.

Location: Hybrid (Must be based in or able to work from Paris or London)

Salary: €65,000 - €85,000

Company

Sustainability data intelligence platform and B Corporation dedicated to empowering companies to manage and reduce their climate impact.

What you will do

• Design and implement end-to-end features, from database schemas and backend logic to GraphQL APIs and React frontend UI.
• Build and operate backend services, including background jobs, async pipelines, and third-party integrations.
• Take full ownership of system reliability, performance, and long-term maintainability.
• Lead technical design on significant features and contribute to the overall technical architecture.
• Own observability by instrumenting systems, defining metrics, and responding to incidents.
• Champion code quality through rigorous pull request reviews and a culture of well-tested, observable changes.

Requirements

• 5+ years of experience in backend development with a track record of shipping at scale.
• Deep command of relational databases, distributed systems, API design, observability, and security.
• Proficiency in building and iterating on frontend features using React and TypeScript.
• Location: Must be based in Paris or London for a hybrid work arrangement.
• Ability to work autonomously in complex systems and deliver across competing priorities.

Nice to have

• Experience with Ruby on Rails, especially in high-scale production environments.

Culture & Benefits

• B Corporation status, focusing on positive social and planetary impact.
• Hybrid work model providing flexibility to balance personal life while staying connected to the team.
• Inclusive environment dedicated to promoting diversity, equality, and equal opportunities.
• Mission-driven culture focused on fighting climate change with high-traction technology.