Principal Software Engineer (Backend & Platform)

Overview

In this role you lead the design, architecture and development of an internal developer platform used by multiple engineering teams. You own tooling, infrastructure and workflows, building a platform from the ground up and guiding the adoption of agentic AI across engineering workstreams. You shape technical direction, standards and guardrails, delivering scalable development environments. The role is hands-on, with significant ownership and impact on innovation, located in Bristol with hybrid onsite requirements.

Responsibilities

• Lead the design, architecture and development of the internal developer platform
• Architect and own tooling, infrastructure, workflows and platform components
• Lead implementation of agentic AI across engineering workflows and rollout coding agents
• Define guardrails for agentic AI (sandboxing, permissions, audit logging, observability)
• Drive CI/CD, infrastructure as code, containers and Kubernetes
• Build and deploy reproducible development environments
• Set technical direction and standards to drive innovation

Key requirements

• Substantial experience as a principal or staff software engineer
• Proficiency across languages/tools/frameworks (Python, Go, Rust, AWS, Kubernetes)
• Experience building developer platforms and internal tooling
• Hands-on experience implementing agentic AI in real workflows
• Experience designing guardrails for agentic AI (sandboxing, permissions, audit logging, observability)
• Deep, hands-on experience with CI/CD, IaC, containers and Kubernetes
• Experience building and deploying reproducible development environments
• Eligible for UK SC clearance

• strong collaboration and leadership
• hands-on, pragmatic problem solving
• ability to set direction and influence cross-functional teams
• Python
• Go
• Rust

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