Senior Software Engineer

Senior Software Engineer (Ada, Simulation / C2 Systems)
Based onsite in Stevenage
Salary up to £64,000 + Bonus | Overtime | Pension
This isn’t a feature factory role.
You’ll be working on simulation software that underpins command-and-control systems, where stability, determinism, and performance actually matter.
A big part of the job is understanding why things break, not just fixing symptoms. You’ll be digging into legacy code, unpicking technical debt, and making changes that stick.
Expect to spend time on:
Root-cause analysis of complex system behaviour
Improving reliability and determinism in simulation environments
Refactoring legacy Ada code where needed, without breaking everything around it
Supporting and improving CI/CD pipelines and automated test coverage
Getting a deep understanding of system architecture, not just your component
Tech-wise, this is a fairly specific stack:
Ada is core; you’ll need to be comfortable working with it day-to-day
CI/CD pipelines and automated testing are part of the workflow
Agile environment, but this isn’t Jira-ticket churn, it’s problem-solving
This will suit someone who:
Enjoys debugging systems at a deeper level
Is comfortable working in existing, complex codebases
Cares about software quality, not just delivery speed
Wants to understand how the whole system behaves, not just their bit
Package includes:
Salary up to £64,000
Bonus
Pension up to 14%
Paid overtime
Up to 15 days flexi leave
Excellent on-site facilities
You’ll need to be eligible for UK security clearance (British citizen or dual national with British citizenship).
If you’re the kind of engineer who gets pulled into the “hard problems” when no one else can fix them, you’ll probably enjoy this.