Job Opportunities API

Sweep is looking for a Senior Fullstack Engineer (freelance) to work on our Sustainability Data Intelligence Platform.     Climate change is the defining issue of our time. Sweep builds a sustainability data intelligence platform used by major enterprises to track greenhouse gas emissions, meet regulatory requirements, and drive real decarbonization. We're a B Corporation, and we mean it.   Ok, sounds promising. What will I be doing?   As a Senior Fullstack Engineer, you'll own features end-to-end, from data models and backend systems to the interfaces that make sustainability data actionable. You'll work at the heart of our core product, alongside a team that cares deeply about quality and impact. What you'll be working on: Build and own core product features - Design and implement full-stack features from the ground up: database schema, backend logic, GraphQL API, and React/TypeScript UI - Take full ownership of significant parts of the system: reliability, performance, and long-term maintainability are yours to drive - Participate in every stage of the development lifecycle, from design and implementation to rollout and smooth operation in production - Contribute to and challenge our technical architecture as we scale Bring genuine backend depth - Design robust data models and schemas built to perform at scale - Build and operate backend services, including background jobs, async pipelines, and integrations with third-party systems - Own observability: instrument systems, define meaningful metrics, and respond to incidents with confidence - Identify and address security risks proactively from API design to infrastructure exposure - Automate deployments via our CI/CD systems and continuously improve development processes Work with AI as a day-to-day accelerator - Leverage AI tools actively in your workflow, from code generation and review to debugging and documentation, to move faster without compromising quality - Contribute to how we integrate AI-assisted development practices across the engineering team - Stay curious about emerging AI capabilities and bring new ideas on how we can use them to ship better, faster Be a team force multiplier - Lead technical design on significant features and share your experience openly - Review pull requests with rigour and care, raising the bar for the whole team - Participate actively in team rituals: stand-ups, planning, retros - Contribute to our culture of quality: incremental, well-tested, observable changes Pursue quality, always - Champion clean code, solid test coverage, and strong engineering practices - Improve processes and methodologies to reach the highest standards - Bring excellence to your own work and help others do the same That sounds just right for me. What do I need to bring?   Glad you asked. This is who we’re looking for: 5+ years of experience shipping product across the full stack, with strong backend foundations Solid experience with Ruby on Rails in a high-scale production environment is a must Fluent in React/TypeScript on the frontend; deep expertise in relational databases, distributed systems, observability, and security on the backend Comfortable owning features end-to-end with autonomy and clear communication You write clean, well-tested code and take genuine ownership of your work   Practical Details Hybrid or Remote. Offices in Paris, London, Montpellier, and Denver Start date: ASAP Duration: Long-term collaboration, renewable Rate: 520€