|
I'm Mattias Avelin, a hands-on CTO and senior Go engineer based in Mälardalen, Sweden. With 20+ years in software and six as a hands-on CTO. I help Nordic tech companies build reliable backend systems, scale infrastructure, and make confident architectural decisions.
Whether you need an embedded senior engineer or part-time technical leadership, I bring both the code and the strategic vision.
Adyen for Platforms, merchant onboarding, KYC, multi-market expansion. I've built this across Sweden and Norway: terminals, digital receipts, the full stack. Before that, payment & fraud systems at Unibet across regulated markets.
I've built and operated ~60 Go microservices for six years. gRPC, Kubernetes, the boring stuff that keeps systems running. I write code, review code, and ship.
I've led engineering teams from 5 to 30+ people, from scrappy startups to scaling organizations. Part-time CTO without the full-time overhead.
SCHREMS II, data sovereignty, migrating off US cloud providers. I've done the research and architectural planning, not just the slide deck.
Claude Code, automated code review, agentic workflows. I've rolled these out with a real team and measured what actually works.
CI/CD, GitOps, automated code review, secure deploys. The kind of infrastructure that lets a small team ship with confidence, repeatedly, not heroically.
When we launched in Italy, the most demanding regulatory market we'd tackled at the time, it took multiple development teams to pull off. But there were moments where you needed someone who could cut through the complexity and actually make the plan work. Player registration, government reporting, core systems needing a rebuild under real deadline pressure. Mattias was that person. He'd push back when something wouldn't fly and come back with something better. He's the kind of engineer you want in the room when the plan meets reality.
When I needed a technical due diligence that I could stake my credibility on with investors, Mattias was the obvious choice. He delivers clarity on complex technical challenges without the jargon, with a genuine focus on business value. It was a natural next step to recommend him as CTO at Dentech to lead their digital transformation. Mattias understands technology as well as the boardroom, and his willingness to stay hands-on is what sets him apart as a leader.
I had the pleasure of having Mattias reporting directly to me during our time at LeoVegas, where he worked as one of my Development Managers in the development department.
Mattias was responsible for leading one of our development areas and played an important role during a period of significant growth, as we scaled the development department from around 80 to approximately 150 people.
What stood out most about Mattias was his ability to balance strong technical understanding with genuine leadership skills. He had a clear focus on including and empowering his team, creating an environment where people felt trusted, involved, and motivated to contribute.
He was always at the forefront when it came to taking initiatives that created real value, not only for his own team but also for the broader department. He combined drive and ownership with a collaborative mindset, making him a strong team player and a valued colleague.
Mattias is also a very good listener, with an empathetic leadership style that helps build trust and engagement. I truly appreciated working with him and would gladly recommend him to any organization looking for a capable, thoughtful, and value-driven engineering leader.
MSc Engineering Physics from KTH, specializing in computer science and computer security. 20+ years in software, from Netlight consulting to payment & fraud systems at Unibet, engineering leadership at LeoVegas, and six years as CTO building a health- and fintech platform from the ground up.
I've done technical due diligence for investors, built cross-border payment infrastructure on Adyen, migrated databases, and shipped products with small teams under real constraints. I care about code quality, team autonomy, and getting things into production.
Deep experience, not just familiarity.
Based in Mälardalen, Sweden. Open to remote or part-time on-site across the Nordics and EU.
