Full-stack Engineer

At Carbon, we’re delegating differently by combining our strong insurance expertise with cutting edge technology. As we rapidly scale globally, and continue to advance Graphene, our proprietary owned data ecosystem, we remain guided by our core pillars of People, Partnerships and Innovation. If you want to join an exciting business powered by the latest technology, and are energised by collaboration, big ideas and making a meaningful impact to our partners, then this role is for you: Full-stack Engineer

About Us
Founded in 2018, Carbon’s mission is to transform delegated underwriting and raise the standard for the industry. Our open underwriting model connects data, insight and people to enable stronger decisions and more dynamic portfolio management, bringing greater transparency, clarity and confidence to our partners and to the way the whole market works.

We’re proud to have been recognised by The Sunday Times as a Best Place to Work in both 2024 and 2025, reflecting our warm, inclusive culture and our energetic, entrepreneurial spirit. Our friendly, modern offices foster creativity and connection, while our partnership with Google Cloud, where we are celebrated as a success story, demonstrates our commitment to innovation and technology at the highest level.

At Carbon, our values shape who we are every day: Win as one, Keep spirits high, Blaze a trail, Speak up, listen up. If you’re looking to join a modern team with bold ambitions and real momentum, we’d love to meet you.

Location:  5th Floor, 9A Devonshire Square. London. EC2M 4YN
Start date:  Immediate
Role type: Permanent, full-time, hybrid

The Opportunity:

Full‑stack engineer role with a strong emphasis on testing and reliability during the first 12 months, while also delivering new features and pragmatic fixes as part of a small team. After the initial reliability phase the role can broaden to other product or platform areas depending on business priorities and candidate strengths.

The Role:

Main Tasks

· Lead testing strategy and delivery: Design and implement a scalable, maintainable testing architecture across Graphene X and Graphene Studio, covering end‑to‑end, integration, API, and UI tests to raise release confidence.

· Proactive reliability engineering: Introduce regression and performance testing, improve observability, and identify systemic risks to prevent incidents before they affect users.

· Full‑stack development: Write production code across the front end and back end, deliver new features, and contribute to architectural decisions that improve product quality and velocity.

· Drive tooling and best practices: Build CI/CD test pipelines, reduce flaky tests, create reusable test components, and document testing patterns and onboarding materials.

· Balance testing with feature work: Prioritise and deliver high‑impact test automation while also shipping feature work and pragmatic fixes appropriate for a small, fast‑moving team.

· Cross‑functional collaboration: Work closely with Product, Data Operations, and Quants to translate user feedback into testable requirements, prioritise work, and demonstrate impact through measurable outcomes.

Skillset/background

We understand no-one can be an expert in all areas. The below gives a guide as to the skills we value:

Essential

· 3+ years engineering experience with demonstrable testing ownership.

· Strong experience with Python, Django, JavaScript/TypeScript and React.

· Hands‑on with test frameworks such as Pytest, Playwright, Cypress or similar.

· Experience building CI/CD test pipelines and working with BuildKite, Google Cloud Build, or similar.

· Strong debugging skills and experience with API testing and mocking.

· Good communication and cross‑team collaboration skills.

Desirable

· Cloud experience (GCP preferred; AWS/Azure also valued).

· Familiarity with observability tools and performance testing.

· Start‑up experience and a product mindset.

· Computer science related degree or equivalent practical experience.