Senior Software Engineer (Backend) in Warminster

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.

Your Role

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.

What you’ll do

• 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.
• 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.

About you

• 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 platforms, data stores and external engines — with a good grasp of integration patterns, authentication and performance.
• Strong in Java (or a comparable backend language you can bring across) and solid SQL — we value the engineer over the exact language.
• Comfortable with version control, code review, automated testing and CI/CD pipelines — you treat test automation and safe, repeatable delivery as part of building, not a separate phase.
• Energised rather than unsettled by ambiguity: you can pick up a new stack quickly, you’re happy to define the problem rather than only solve a specified one, and you make sound calls when requirements are still moving.
• Sound judgement around system and data design — including integrating with a data warehouse / lakehouse — and good instincts for when to use streaming or event‑driven approaches versus batch.
• Pragmatic about quality: you instrument what you build and care as much about how it runs in production as how it looks in code review.
• A strong communicator who can hold a technical conversation with engineers and a plain‑language one with project managers, designers and senior customer stakeholders — internal and external, including in regulated environments.
• A mentor by instinct who lifts the people around you and helps spread good practice.
• Fluent written and spoken English, as required for security‑cleared defence work and for clear communication with UK customer stakeholders.

This role requires the successful candidate to be a UK national and eligible to obtain UK Security Clearance (SC). Candidates who already hold current UK SC clearance will be at an advantage; however, we also welcome applications from individuals who meet the eligibility requirements and are willing to undergo the SC clearance process.

A genuine interest in our mission — software that helps armed forces, public safety and resilience organisations train, prepare, and respond.

Research shows some people only apply when they meet every requirement — if you don’t tick every box but recognise yourself in much of the above, please apply anyway. We’d genuinely like to hear from you.

What you can expect from 4C Strategies

• Warminster‑based, with hybrid working — typically around three days a week on‑site at our office or a customer site. Some of the work needs to be done on‑site, and the exact pattern can vary with the programme’s needs, but we’re supportive of flexibility where the work allows.
• Easily commutable from Bath, Salisbury, Trowbridge and the surrounding area.
• Competitive salary, reviewed annually.
• Pension Scheme with 5% employer contribution.
• Private healthcare including dental.
• Enhanced family leave (maternity, paternity and adoption).
• 25 days holidays (plus bank holidays).
• Life Assurance.
• Cycle to work scheme.
• Work Extras Discounts at over 80 retailers.
• Company social events.

Why Join 4C Strategies

If you’re happiest when the path isn’t drawn yet, this is a rare chance to own hard, open problems on a large, multi‑year programme — real scale, real production systems, and the freedom to shape how they’re built — with a collaborative team to figure the hard parts out alongside you. You’ll work alongside experienced engineers and military specialists, with the individual‑contributor track valued as highly as management, so you can grow without leaving the code behind. The work matters: what you build helps armed forces, public safety and resilience organisations train, prepare, and respond. If you want senior‑level ownership on systems that are used in earnest — not a backlog ticket factory — this is that role.

4C Strategies is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees.