Senior Software Engineer; Backend

Who We Are

4C Strategies builds organisational readiness and military training management software for clients in over 70 countries. Our flagship product, Exonaut®, is used by NATO and allied forces to plan, run and evaluate exercises in real time. Our consultants and engineers work alongside armed forces across the UK, Europe, North America and beyond to deliver training and exercise management solutions.

Much of this hasn’t been designed yet — and that’s the point. We’re connecting Exonaut to a fast-growing landscape of systems (a data lakehouse, customer ERP platforms, optimisation engines, partner platforms) on one of the most significant training transformation programmes in UK defence, and a lot of the hard problems are still open. We want a senior backend engineer who’s energised by that kind of ambiguity: someone who can take a vaguely-defined need, work with the team to figure out the right shape, and build it.

You’ll own and evolve parts of the Exonaut® platform itself, not just wire systems together — real product engineering at the seams of several moving parts. Scope will shift, requirements will surprise you, and — with the support of a strong team around you — you’ll have the autonomy to make the calls that matter. This sits within a large, multi-year MoD programme — one of the most significant training transformation efforts in UK defence today.

This is a Senior role with real ownership. You’ll lead substantial pieces of work end-to-end — designing, choosing the right patterns, and seeing them through to production — and help shape how the wider team works: the standards we hold ourselves to, the tools we reach for, and how we test and observe what we build.

Day to day you’ll collaborate with other engineers, project managers and designers on the programme, with senior stakeholders on the customer side, and with peers across the wider 4C engineering organisation — where the IC track is treated as a first-class career path alongside management.

• Figure out and build how Exonaut talks to everything around it — a data lakehouse, customer ERP systems, optimisation engines and partner platforms — often from a rough idea rather than a finished spec, reading and writing data reliably with maintainability, observability and security designed in from the start.
• Work across a modern data and backend stack — built around Java and SQL databases — alongside pipeline orchestration and transformation tooling, choosing the right tool for the problem rather than the other way round. Big parts of the stack are still ours to decide — you’ll make real architecture calls, not inherit someone else’s, so judgement and pragmatism matter more than experience with any one tool.
• Introduce event-driven and change-data-capture (CDC) patterns where they help us keep data flowing in near-real-time across systems.
• Help raise our engineering standards around code quality, automated testing, CI/CD and observability — building the pipelines and test automation that let us ship changes safely and often, with quality and operability treated as first-class engineering concerns, not an afterthought.
• Mentor and coach engineers across the team — not just juniors — and help grow our backend and integration engineering practice inside 4C.
• Extend and modify the existing Exonaut platform, building the backend services and APIs that connect it to surrounding systems — owning integration contracts, performance and security.
• Work directly with stakeholders on both sides — our own project managers, designers and engineers, and the customer’s technical and non-technical people — drawing out what’s really needed, explaining technical trade-offs in plain language, and making sure what we build genuinely serves the people who use it.

• A capable engineer with backend and data experience who has independently led substantial pieces of integration, backend or data work — connecting systems together and seeing it through to production — and who still likes being close to the code.
• Comfortable building backend services and APIs (REST and/or event-based) and integrating with third-party systems such as ERP…