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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Platform Engineer - **Company:** Refractal - **Location:** Greater London, UK - **Contract:** Permanent contract - **Skills:** Application Programming Interfaces (APIs), Audit Trail, Cyber Security, Continuous Integration, Relational Databases, Human-Computer Interaction, Python (Programming Language), PostgreSQL, Open Source Technology, SQLite, SQLAlchemy, Management of Software Versions, Web Services, Real Time Systems, Grafana, Backend, Fastapi, Data Layers, Database Migration, Build Management, Api Design - **Published:** August 30, 2026 - **Apply:** https://www.collegerecruiter.com/job/2828452137-platform-engineer ## About the Role We assess demonstrated ability, rather than a specific credential or number of years in industry. You should have: * Strong backend experience with HTTP APIs. Experience with Python and FastAPI, or similar tools, is preferred. * Experience with observability and tracing systems. You can trace agent actions, tool calls, requests, spans and enforcement decisions across services. * Experience with relational databases. This should include Postgres or SQLite, SQLAlchemy and database migrations. * Experience in API design, versioning and compatibility. You can create SDKs, documentation and examples that make integration simple. * A good understanding of authentication, sessions, API keys, authorisation and multi-tenant access control. * Experience with data models, event streams, audit records and error handling. * The ability to work independently, communicate clearly and take ownership of technically uncertain customer problems. Particularly strong signals include: * An external API or SDK that you owned from the data model to customer use. * Experience with B2B or enterprise integrations, especially where trust, auditability or compliance was important. * Experience with data-dense or real-time systems, such as security consoles, observability tools, event streams or SSE. * Experience with containers, continuous integration and deployment, and cloud platforms such as GCP Cloud Run and Cloud SQL. * Experience in AI security, cyber security or another high-assurance technical field. * Open-source or side-project work that shows clear engineering decisions and good product judgement. ## Description The Role: Platform Engineer As a Platform Engineer, you will own the core product platform from the external interface to the service and data layers. Your main focus will be the APIs and SDKs that customers use to connect Refractal to their systems. You will also build the FastAPI services, authentication, multi-tenant isolation, data contracts and event interfaces that support these integrations. You will build customer onboarding, policy integration and operator tools. Refractal also has a dashboard that helps security teams inspect activity, review evidence, manage policy and act on enforcement decisions. The dashboard is powered by the core APIs and services that support customer integrations. You will work directly with the founders and early customers. You will convert operational security needs into simple and reliable platform interfaces. You will also help set the technical direction, engineering standards and product roadmap., * Own the platform API and its SDKs. Define stable, versioned contracts, clear client interfaces, error behaviour, compatibility rules, documentation and examples. * Design and build the FastAPI services behind these interfaces. Provide access to enforcement decisions, evidence, policies and red-team results. * Own identity and access at the platform layer. This includes authentication, sessions, API keys, authorisation and multi-tenant access control. A tenant must never have access to another tenant's data. * Design the platform's data and event interfaces. This includes read models, request and span records, real-time SSE streams and a tamper-evident audit ledger. * Present security data accurately. The API, SDKs and user interfaces must clearly identify data that is missing, not measured or not captured. They must never create false values. * Build the customer integration and onboarding flows. This includes tenant setup, policy binding, integrations, sign-in and API-key issue. * Build the operator dashboard as a client of the platform API. It includes the agent-action heatmap, attacker trajectories, traces, policy compiler, decision traces and audit ledger. * Work directly with customers. Understand their systems and operating processes, then convert these needs into clear product requirements. * Define engineering standards for APIs, SDKs, components, tests and customer-facing quality. What We Are Looking For We need a product-minded platform engineer who takes end-to-end ownership. You can work from the data model to the external API, SDK and customer integration. You can also build operator tools when required. You make complex systems clear and predictable. You understand that an incorrect permission, an unstable API or a misleading user interface can cause a serious security fault. You deliver small, correct changes and improve them with evidence. You do not spend months designing an abstraction before you test it. You use real system data and do not hide missing data with false or cosmetic states. Most importantly, you want to build the platform that security teams use to deploy autonomous systems safely at scale. ## Related Videos - [Inside Bitpanda's Tech Stack: Scaling a European Fintech Leader - Markus Dorner](https://www.wearedevelopers.com/videos/1979-inside-bitpanda-s-tech-stack-scaling-a-european-fintech-leader-markus-dorner) - [Intro to FastAPI](https://www.wearedevelopers.com/videos/462-intro-to-fastapi) - [Introduction to TXT](https://www.wearedevelopers.com/videos/30-introduction-to-txt) - [Developing the Backend with Stefan Lingler, CTO at Shpock](https://www.wearedevelopers.com/videos/100360-developing-the-backend-with-stefan-lingler-cto-at-shpock) - [Meet Your New BFF: Backend to Frontend without the Duct Tape](https://www.wearedevelopers.com/videos/682-meet-your-new-bff-backend-to-frontend-without-the-duct-tape) - [Building and Deploying Multi-Agent Systems with ADK and Vertex AI](https://www.wearedevelopers.com/videos/1918-building-and-deploying-multi-agent-systems-with-adk-and-vertex-ai) ## Related Articles - [The 7 Most Popular Backend Frameworks for Developers](https://www.wearedevelopers.com/magazine/403-the-7-most-popular-backend-frameworks-for-developers) - [Why Upskilling And Reskilling is Important For Developers](https://www.wearedevelopers.com/magazine/428-why-upskilling-and-reskilling-is-important-for-developers) - [Fully Remote Software Engineer Jobs](https://www.wearedevelopers.com/magazine/447-fully-remote-software-engineer-jobs) - [Data Engineer Salary UK](https://www.wearedevelopers.com/magazine/253-data-engineer-salary-uk) - [Software Engineer Salary London](https://www.wearedevelopers.com/magazine/252-software-engineer-salary-london) - [Where To Find Software Engineering Jobs](https://www.wearedevelopers.com/magazine/396-where-to-find-software-engineering-jobs)