Principal Software Engineer (Backend & Platform)

Our client is a fast-growing UK engineering and software technology company located in Bristol. They are looking to hire a Principal Software Engineer to lead the design, architecture and development of their internal developer platform that all their engineering teams will utilise and depend on. You will architect and own the tooling, infrastructure, workflows, and components that their developers build on. This will be a platform built from the ground up for agentic engineering- so you will lead the implementation of agentic AI and champion its use ie roll out coding agents across engineering workflows and own how and where they're used.

Key skills/experience required:

• Substantial experience as a principal or staff software engineer, with experience of utilising a range of languages/tools/frameworks (Python, Go, Rust, AWS, Kubernetes, etc)
• Demonstrable experience building developer platforms, internal tooling, and paved paths used by engineering teams.
• Hands-on experience implementing agentic AI in real engineering workflows (beyond individual experimentation).
• Experience designing the guardrails around agentic AI: sandboxing, permissioning, audit logging, or observability for tools operating with elevated access.
• Deep, hands-on experience of CI/CD, infrastructure as code, containers, and Kubernetes.
• Experience of building and deploying reproducible development environments.

Why consider it?

This is a genuinely hands-on Principal role with significant technical ownership where you can set technical direction and standards, to drive innovation.

The role is hybrid, with a minimum of 3 days per week onsite in Bristol, and candidates must be eligible for UK SC clearance.