Senior Software Engineer (Full Stack)

Who we are

4C Strategies builds readiness and resilience software for defence, public safety and critical infrastructure organisations in more than 70 countries. Our Exonaut® platform is used to plan, run and evaluate large-scale training, exercises and capability evaluations, and our consultants and engineers work alongside those organisations across Europe, North America and beyond.

What we're building

We're building the evidence layer for defence experimentation and evaluation. When an organisation tests a new capability — a sensor, an autonomous system, a different way of operating — it has to be able to defend the result afterwards, to someone who was not there and who has every reason to challenge it. Today that evidence lives in spreadsheets, documents and standalone survey tools, and it cannot be traced from a conclusion back to the observation that supports it.

Our platform fixes the structure before the data is collected, captures evidence from people and from machines, fuses it into chains that carry their own provenance, and keeps every finding traceable to its source. The hard part is not the plumbing. It is holding one coherent model steady while every customer arrives with their own vocabulary, their own method and a reasonable-sounding request for one more special case.

How we build

Modern Java — currently 25 — and Spring Boot on a modular JPMS architecture, an Angular 21 single-page application, PostgreSQL with PostGIS, deployed to Kubernetes.

The principles are conservative on purpose. Dependency inversion at every module boundary: contracts in an API module, implementation separate, no reverse dependencies. Schema evolution is explicit and reversible, through migrations with rollback scripts and no auto-DDL in any environment. Evolutionary change over rewrites, with a staged path when a domain concern outgrows its boundary. Structural decisions are argued in RFCs and recorded in ADRs, and changes to the core domain model go through that process rather than around it — because that model is the product, and it is the thing most easily damaged under delivery pressure.

Three constraints shape most of what we do. It runs inside the customer's own environment: single-tenant, sovereign, accredited, sometimes with no route to the internet at all, so nothing may assume a managed cloud service. Evidence has to be captured where the work happens, which means a tablet in a field with no connectivity and a sync that loses nothing. And the audit trail is immutable — evidence cannot be quietly deleted or backdated, and no automated process publishes a conclusion without a person taking responsibility for it.

You

We are a small team, so you will work across the stack rather than behind a specialism. Substantial experience in either Java or TypeScript, and a genuine willingness to be useful in the other. Sound judgement about data modelling, because most of the interesting problems here are modelling problems wearing engineering clothes. Comfortable with ambiguity: requirements move, and the shape of the answer is often the work.

A real advantage, though none of it is required: sovereign, air-gapped or accredited deployments; offline-first or sync-heavy applications; geospatial data; sensor, telemetry or simulation integration; audit and traceability requirements. The domain is learnable, the judgement less so.

The team is small enough that your work is visible and your arguments carry. Your designs will be challenged and you will be expected to challenge back — including on scope.

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.

Security and citizenship

This role supports defence work, so the successful candidate must hold Swedish citizenship and pass Swedish security vetting (säkerhetsprövning). We will explain what the check involves early in the process rather than late — a requirement like this should never be a surprise at offer stage.

This requirement comes only from the security rules that govern defence work, not from personal preference.

Why it matters

Capability decisions get made on this evidence. When an organisation concludes that something is ready, or that it is not, that judgement has consequences for the people who depend on it. Making it defensible is the whole point.

How we hire

Every interview has a written script and a scored rubric, applied the same way to every candidate.

• Hiring Manager Screen — a conversation about your experience, how you work and what

you want next.

• System Design — a design discussion drawn from problems like the ones above.

• Programming — a hands-on session in a language of your choice (Java, C#, TypeScript,

Python or Go).

• Culture Interview — how you collaborate, disagree and make decisions with others.

• Candidate Q&A — your time to interrogate us. We expect you to use it.

We then debrief as a panel and decide. We review applications on a rolling basis.

What you can expect from 4C Strategies

• Stockholm-based, with hybrid working.

• Competitive salary, reviewed annually.

• Occupational pension (tjänstepension).

• Wellness allowance (friskvårdsbidrag).

• Healthcare insurance, including insurance for treatment.

• Parental pay.

• Vaccinations.

• A supportive, collaborative team building meaningful products for mission-critical work.

Why join 4C Strategies

This is a small team with a large surface. You will not be handed a narrow lane: the platform is still being shaped, the domain model is still being argued about, and the person who makes the argument well is the person who decides. If you would rather own a hard, open problem end to end than take tickets from a backlog, that is the job.

The work matters: what you build helps defence, public safety and resilience organisations prepare for the situations they hope not to face.

How to apply

To apply, click the Apply today button and submit your CV. A short cover note on your experience and motivation is welcome but not required. We review applications on a rolling basis, so please apply as soon as you can.

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