Platform Engineer – AI Security Infra (London)

Refractal; Greater London; On-site; GBP 60,000 - 115,000; Full time

Benefits offered by this job

Equity

Bonus

London-based, in-person work

Visa sponsorship support

Job summary

Refractal in London is seeking a product-minded platform engineer to own core platform APIs and SDKs from data model to customer integration. You will build enforcement decision services, authentication, and multi-tenant controls, collaborating directly with the founders and early customers to turn security needs into reliable interfaces.

You will design real-time data interfaces, event contracts, and operator dashboards, while ensuring compatibility, testing, and deployment across Cloud Run and

Qualifications

• Experience designing and building HTTP APIs with clear versioning and documentation.
• Strong understanding of authentication, authorization, API keys and multi-tenant access control.
• Experience with observability, tracing, relational databases, and migrations.

Responsibilities

• Own stable, versioned platform APIs and SDKs, including client interfaces and examples.
• Build FastAPI services for enforcement decisions, evidence, policies, and results.
• Design authentication, sessions, API keys, authorisation, and 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.

Skills

HTTP APIs

Observability

Relational databases

API design & versioning

Authentication & Authorization

React

Tools

Python

FastAPI

Cloud Run

Cloud SQL

Job description

Refractal in London is seeking a product-minded platform engineer to own core platform APIs and SDKs from data model to customer integration. You will build enforcement decision services, authentication, and multi-tenant controls, collaborating directly with the founders and early customers to turn security needs into reliable interfaces.

You will design real-time data interfaces, event contracts, and operator dashboards, while ensuring compatibility, testing, and deployment across Cloud Run and