Senior Software Engineer

X-Lab is offering an exciting opportunity for a Senior Software Engineer to join our small, fast-moving engineering team. You'll work across the full stack on our product suite, building features in C#/.NET and React with TypeScript, and you'll own the infrastructure for the things you ship. We run everything as code, all Terraform and no click ops, and every engineer looks after their own Azure platform.

As a senior member of a team of six engineers, we'll look to you for more than delivering your own work well: you'll shape the architecture and technical direction of our products, lead a product area end to end, and help raise the bar for the whole team. We have the pace and ambition of a start-up, so we're looking for someone who enjoys variety, takes real ownership, and wants to help us grow.

This is a genuinely AI-native team. Claude Code is part of how every engineer works here, and as a senior engineer we want you to help take that further, shaping how we build our own skills and plugins so the tools understand X-Lab specifically. None of that means we care less about the craft: we still read, understand, and take real pride in the architecture and code we ship, and the judgement calls stay firmly with us.

About the Role

You'll spend most of your time building product, working across a C#/.NET back end and a React and TypeScript front end, from the interface a lab uses day to day to the services that move diagnostic data between organisations. As a senior engineer, you'll take ownership of a product area end to end, set the technical direction for it, and make the architecture calls that keep it healthy as it grows. Because every engineer owns their own infrastructure, your work doesn't stop at the code: you'll provision and maintain what you ship with Terraform on Azure, to the same standard as the rest of the team.

Beyond your own delivery, we'll look to you to raise the bar for everyone. That means reviewing code thoughtfully, mentoring the engineers around you, and helping set sensible standards for how we build, secure, and operate software. There are no formal reports attached to this role. The influence here is technical rather than managerial, but we expect you to be someone the team learns from.

The way we work is genuinely AI-native, and it isn't a bolt-on. Every engineer uses Claude Code every day, Claude reviews every pull request before a human does, and we build our own skills and plugins so the tools understand X-Lab specifically. As a senior engineer, we want you helping to shape how we do this: deepening our internal tooling and setting the example for how the team gets the most from it. Claude advises, but people still make every call on what merges and what ships.

Key responsibilities

• Design, build, and ship features across the stack on our product suite, in C#/.NET and React with TypeScript.
• Take ownership of a product area end to end, leading its architecture and technical direction as it scales.
• Own the infrastructure for what you build, provisioning and maintaining it as code with Terraform on Azure.
• Work in an AI-native way day to day, and help deepen our internal skills and plugins so the whole team gets more from tools like Claude Code.
• Set and uphold a high quality bar through code review, mentoring, and sensible standards.
• Mentor the engineers around you and share what you know, raising the standard of how we build and operate software.
• Contribute to architecture and technical decisions across the wider product suite, not only your own area.
• Build features that are reliable and operable from day one, with monitoring and alerting in mind.

About You

Essential

• Significant commercial experience as a software engineer, comfortable owning substantial pieces of work end to end.
• Full-stack development experience with C#/.NET and React.
• Working knowledge of TypeScript.
• A track record of shaping architecture and technical direction, and of making pragmatic trade-offs that hold up over time.
• Experience raising the bar around you, whether through mentoring, code review, or setting technical standards.
• Comfortable with, or genuinely keen to adopt, an AI-native way of working, using agentic tools such as Claude Code as a core part of daily development rather than an occasional extra.
• A willingness to own your own infrastructure, or the appetite to learn: we'll support you with Azure and Terraform if these are new to you.
• A pragmatic approach: you can tell the right long-term solution from what's good enough for now.
• Excellent written and verbal communication, able to explain technical trade-offs clearly.
• Comfortable working remotely and self-motivating.

Desirable

• Hands-on experience with Microsoft Azure.
• Experience with infrastructure as code, particularly Terraform.
• Experience owning your own infrastructure rather than handing it to a separate ops team.
• Experience leading a product area or a significant technical initiative.
• Experience in healthcare, health tech, SaaS, or other regulated environments.
• Exposure to data protection and privacy concepts (for example GDPR, HIPAA).
• Familiarity with containerisation and orchestration (for example Docker, Kubernetes).

Benefits

• Unlimited annual leave policy.
• Meaningful EMI options package.
• Remote working and flexible working hours.
• Company outings, social events and wellbeing initiatives.
• Birthday meal.
• Life Insurance.
• Comprehensive Employee Assistance Programme.

Please apply by submitting your CV and answer all application questions.