Lead Full Stack Engineer

LEAD FULLSTACK SOFTWARE ENGINEER 12 month Contract 2-3 days per week in Westminster, London £650 - £700 per day inside IR35 TXP are looking for a Lead Fullstack Software Engineer to join our clients team. Working alongside existing developers, tech leads, and the platform group. This is application and service-level work, not infrastructure at the network or hardware layer. The separate Platform Engineering team owns the underlying cloud infrastructure, networking, and shared platform services; this role operates at the application layer, consuming and collaborating with the platform rather than owning it. Responsibilities Lead the migration of services off the London Datacentre onto AWS and Kubernetes, with .NET 10 as the target runtime Build and maintain shared service templates, libraries, and patterns so the wider team can converge on a consistent, modern estate Design and build migration pipelines that combine Terraform, CI/CD, and AI coding agents to refactor and move services at scale, including adding test coverage as part of the migration step Work with the platform team on observability, networking, and dependency management as services land in the cloud estate Required Experience Strong C# and .NET development experience (at least 8 years), including modern .NET and familiarity with the .NET Framework constraints typical of legacy estates Hands-on AWS experience, building g, deploying, and operating production workloads Production experience with Kubernetes, including deploying and operating workloads on K8s in a cloud environment Strong Terraform skills and a track record of using infrastructure-as-code to provision and manage cloud environments Comfortable working through authentication issues across a mixed estate, including handling legacy mechanisms and bringing services onto modern, token-based patterns Experience with SQL Server Active day-to-day use of agentic coding tools such as Claude Code, Codex, or equivalent, with a willingness to drive substantial refactors and migrations through them rather than by hand Desireable Experience Python development for tooling, automation, and pipeline work Experience leading large legacy-to-cloud migrations, particularly off on-prem Windows estates Experience designing service templates or "golden paths" that other engineers adopt and build on Familiarity with observability tooling, including metrics, tracing, and structured logging across distributed services