Senior Software Developer

Senior Software Developer – Full Stack

Do you want to shape the software that keeps allied nations connected on the battlefield? As a Senior Systems Engineer on our IRIS team, you'll lead feature development across a rich technology stack — and leave your mark on military messaging software trusted by more than 50 nations worldwide.

The job

You'll take ownership of new features from design through to delivery, working across both modern and legacy code in a fast-moving environment where no two weeks look the same. Alongside hands-on development, you'll help less experienced colleagues grow — acting as a technical guide and keeping quality high across the team.

In short, you can look forward to:

• designing and implementing new features in the IRIS suite, Systematics military messaging and interoperability platform

• maintaining and improving legacy code across the back end

• documenting solutions and describing technical designs for the wider team

• mentoring junior developers and reviewing their code

• contributing to technical assessments as part of the hiring process on an occasional basis.

**Joining the team

The IRIS team exists to create interoperability between coalition forces — ensuring that nations can share critical information and carry out successful missions together. You'll be part of a close-knit group of 23 people, including developers based in Denmark, Romania, and the UK, alongside architects, testers, a UX specialist, and a programme manager. It's an environment where the technical scope shifts regularly, keeping the work genuinely varied, and where there's a clear path for those who want to grow into architecture or design. The team values learning from mistakes, honest communication, and getting things done pragmatically.

Your qualifications

• a relevant degree or equivalent professional education

• a minimum of five years' experience in software development

• solid proficiency in at least one object-oriented programming language, preferably java — other than that the team works with JavaScript, C++, and C#

• experience designing software solutions and producing technical documentation

• fluent English, both written and spoken.

Please note that you must be able to present a clean criminal record and have lived in a NATO and/or EU country for the past seven years, as we work with security-classified projects. Read more here.

Welcome to Systematic Aarhus

At our Aarhus office, you can look forward to joining our Employees Club, which offers nearly 100 events a year of both social and professional character. Here, you can take advantage of a range of on-site perks from physiotherapist-led massages and an in-house hairdresser to sports clubs, game tables and even our own padel court. Our canteen is a standout feature, serving a daily selection of delicious and healthy dishes. Beyond the office, you'll also enjoy benefits like free ARoS +1 access and various shopping discounts.