Senior Full Stack Developer
First seen by Alion on Oct 12, 2026.
Senior Full Stack Developer – join a development team working with telecom, automation and rock-solid UX at Adversus A/S in Aarhus.
Are you a developer who can put together an excellent performing application platform on top of a complex system? Do you have a solid feel for UX, software design and the technical chops to bring everything together into one neat package? Then (please) don't shy away and continue reading. This position could be yours!
Adversus' ambitions are high, our organization is flat, and we always strive to learn and have fun while doing it.
Since 2016, Adversus has strived to be a market leader in a competitive field that requires high availability and high uptime. Adversus has experienced exponential growth in recent years, both in demand of the product itself but also the company. Today, we have 70+ employees located at our headquarters in Aarhus.
Adversus' solution is an all-in-one sales acceleration platform that supports our customers' needs for an effective, structured and data-driven daily routine. Delivering an efficient and stable experience with a high level of usability is key to our high user satisfaction.
When spending most of their day on our platform, our users often need deep insights into their data and are always looking for ways to optimize their setup. Our platform unites three different tools: a telecommunications system, an automation system and a CRM system. Because of these many moving parts, our application needs to handle the unexpected and present a solid user experience even when something, somewhere, isn't working.
As our new senior full stack developer, you'll be welcomed with open arms by our Development team to deliver the next generation of our software.
Your primary responsibilities will be implementing new features and services that extend the capabilities of our main application, as well as improving the existing ones. This includes work on our various automation systems, on-demand, large-scale task processing, and keeping our integrations up to date. You will also be expected to work with our frontend application, helping improve some of the technical views and sometimes prototyping new interfaces for new features.
As a senior developer, you will be expected to see the bigger picture — understanding how individual pieces of work fit into the platform as a whole, and helping the team make good technical decisions along the way. You will naturally take ownership of complex problems, including the genuinely open-ended ones where you're the one figuring out where to start, and reduce their complexity for the rest of the team. You'll take full ownership from scoping to delivery: defining the approach, coordinating with whoever the work touches, and seeing it through, not just the technical parts.
You'll also help junior and mid-level colleagues grow through code reviews, knowledge sharing and day-to-day collaboration. You'll act as a go-to resource for technical decisions and code quality, taking the time to explain your reasoning, not just hand over the answer, and helping people get better at what they do.
You should be deeply familiar with async processing flows, data-driven programming, and be able to implement them confidently both on the backend and frontend.
You should be comfortable working with new technologies, and some very old ones, and be able to hit the ground running on problems where you may not know all the details up front — including ones nobody has fully defined yet, where you're happy to take the first step yourself.
Our tech stack, in brief:
React / Typescript / Tailwind
PHP / MySQL / NodeJS / Redis
And some of the extra flavor you will probably end up interacting with:
Elastic search / WebRTC / SignalR / RabbitMQ
We are looking for someone with more than 5 years of professional experience as a full stack developer. A relevant degree is a plus, but what matters most is that you have the technical chops and experience to genuinely call yourself senior — how you got there matters less than the fact that you did.
You’re a pragmatic problem solver who gets things done: you can dig into an unfamiliar technology or protocol, form a view quickly, and make decisions backed by solid, critical arguments. You’re comfortable committing to a direction without needing every detail up front, and delivering business-critical work on a tight deadline. You have solid experience across our core tech stack and are ready to take on a challenge when it comes to the rest. You have seen enough systems and codebases to know how things can go wrong, and you use that perspective to write better code, spot risk early, and guide others.
You take real ownership of what you work on, and you're just as comfortable picking up a loosely defined problem and figuring out where to start as you are executing against a clear spec. You have a good sense for how the pieces of a system fit together, and you are comfortable being a go-to resource for your colleagues, including helping them grow, without needing a formal leadership title.
You communicate effectively in English – Danish is not a requirement.
As a person, you are disciplined, reliable, and a natural team player. You take ownership and understand how your work contributes to customer outcomes. You are curious about new technologies and unafraid of some old ones. Lastly, you are happy to be part of a humorous, collaborative work environment.
We keep it straightforward and respectful of your time:
CV screen — we review your application and reach out for a quick 10 min call for further clarifications
First interview — a conversation about you, your experience, and the role, preferably in person at our office
Technical assignment — a practical task to complete in your own time
Second interview — a technical conversation with our team based on the assignment
We offer you a full-time job with an attractive and competitive salary package to match your qualifications and experience. We recently moved into a newly renovated and decorated office space located right in the heart of Aarhus, so if you value excellent working conditions, we think we got that covered too. We're pretty flexible about meeting times, but we expect that you are able to come to the office most days of the week, while having the option to take 1-2 work from home days per week if needed.
You will have full health and dental insurance, pension, and an IT setup tailored to your preferences.
We have a Choose Your Own Lunch catering solution, so you never have to go hungry; and plenty of social events like Friday bars, out-of-office gatherings, and summer parties.
Salary and terms of employment are negotiated individually.