Senior Fullstack Engineer (Freelance)

Sweep

14d•Hybrid

About The Position

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.

Requirements

5+ years of experience shipping product across the full stack, with strong backend foundations
Fluent in React/TypeScript on the frontend
Deep expertise in relational databases, distributed systems, observability, and security on the backend
Comfortable owning features end-end with autonomy and clear communication

Nice To Haves

Ruby on Rails experience in a high-scale production environment

Responsibilities

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
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
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
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
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