Platform Engineer

About the role

Refractal is seeking a product-minded platform engineer to own the core product platform, including external interfaces, service layers, and data layers. You will build APIs and SDKs that connect the platform to customer systems while working directly with founders and early customers to translate security needs into reliable tools. This role involves managing the full lifecycle of platform components, from design and development to testing and deployment.

Responsibilities

• Own stable, versioned platform APIs and SDKs, including client interfaces, compatibility rules, documentation, and examples.
• Build FastAPI services for enforcement decisions, evidence, policies, and red-team results.
• Design authentication, sessions, API keys, authorisation, and rigorous multi-tenant isolation.
• Build data and event interfaces, real-time streams, and a tamper-evident audit ledger.
• Create customer onboarding, policy integration, and operator dashboard workflows.
• Own testing and deployment across API compatibility, browser smoke tests, Cloud Run, and Cloud SQL.

Required skills

• Backend development
• HTTP APIs
• Observability
• Tracing
• Relational databases
• Database migrations
• API design
• Authentication
• Authorisation
• Multi-tenant access control
• JavaScript
• React

Nice to have

• Python
• FastAPI

Benefits

• Competitive salary
• Equity
• Performance-linked bonus
• UK Skilled Worker visa sponsorship
• Global Talent application support

About the Company

Refractal is an AI security company building infrastructure to defend against autonomous AI threats. Founded by experts from MIT, Microsoft, NASA, and the U.S. Navy, the company combines proven cybersecurity methods with frontier AI research to protect critical organisations.