Platform Engineer

Principal Platform Engineer – AI-Native Developer Platform London (Hybrid) Up to £150,000 base + bonus + benefits We're partnering with a leading financial services firm to recruit a Principal Platform Engineer to help design and build a new AI-native developer platform from the ground up. This is an opportunity to shape how software is developed across a major financial services organisation, creating the tooling, reusable engineering patterns and automated controls that enable both software engineers and AI coding agents to build and deploy applications securely and efficiently. We're looking for someone who combines strong hands-on software engineering experience with AWS platform development and a genuine interest in AI-native engineering. This is not a traditional DevOps, infrastructure or SRE role. The emphasis is on building software, APIs and developer tooling that improve how engineering teams deliver applications. The opportunity You'll join a team developing a new internal developer platform designed to make the secure, compliant and efficient way of building software the easiest way. The platform will provide self-service capabilities, reusable development patterns and automated governance, supporting both human developers and increasingly autonomous AI coding agents. You'll play a key role in shaping the platform's architecture while remaining actively involved in hands-on engineering. Key responsibilities - Design and develop AWS-native applications, APIs and platform services that form the foundation of a new internal developer platform. - Build self-service developer tooling, including APIs, command-line interfaces and management capabilities. - Create reusable engineering patterns, application templates, golden paths and AI agent skills that accelerate software development across the organisation. - Develop automated security, compliance and governance controls embedded directly into engineering workflows. - Build integrations with enterprise systems including AWS, GitHub, identity platforms and data services. - Use AI coding agents and AI-assisted development tools to improve engineering productivity, quality and delivery. - Establish modern engineering practices around automated testing, infrastructure as code, CI/CD and observability. - Collaborate with engineering, security and architecture teams to drive platform adoption and continuous improvement. Technical environment The platform is being developed using a modern cloud-native stack, including: - Cloud: AWS, Lambda, API Gateway, Step Functions and event-driven architectures. - Software engineering: Python, FastAPI, TypeScript, APIs and microservices. - Infrastructure and delivery: Terraform, GitHub Actions, GitOps and automated testing. - AI-native engineering: Claude Code, Cursor, GitHub Copilot, MCP, reusable agent skills and agentic development workflows. - AI services: AWS Bedrock and related AI platform capabilities. - Security: Identity federation, OIDC, automated controls and secure-by-design engineering. What we're looking for - Significant hands-on software engineering experience, ideally progressing into platform engineering, developer tooling or cloud-native application development. - Strong AWS experience, particularly building production applications using serverless and event-driven services. - Experience designing and developing APIs, microservices and reusable software components. - Practical experience with infrastructure as code, ideally Terraform. - Strong knowledge of CI/CD, GitHub Actions and modern software delivery practices. - Experience building tooling, automation or reusable capabilities that improve developer productivity. - Genuine hands-on exposure to AI-assisted software engineering and coding agents. - Ability to operate at Principal Engineer level, influencing technical direction while continuing to write production code. - Building internal developer platforms, developer portals, CLIs or golden paths. - Developing MCP integrations, agent skills or agent-enabled engineering workflows. - AWS Bedrock, AgentCore or broader agentic AI technologies. - Experience with contract-first API design, test-driven development and automated policy enforcement. - Working within financial services or another highly regulated environment. If you're a hands-on Principal, Staff or Senior Software/Platform Engineer with strong AWS experience and an interest in shaping the future of AI-native software development, apply now.