Senior-led. No unnecessary layers.
Founded in 2017, Thelan is a small, senior-led development team covering custom software and front-end engineering. We believe good software comes from direct access, honest communication, and a clear understanding of how your business works. The people you speak to are the people who build your software. Our clients include pharmaceutical companies, global automotive brands, and enterprise organisations with complex operational and compliance requirements — across Greece and the US.
Direct Access to Senior DevelopersYou work directly with the senior developer leading your project — from the first conversation to final delivery. No account managers, and nothing reaches you without senior review.
Built to last, not just to launchWe write clean, structured code and hand over systems your team can actually maintain and extend.
Delivering production systems for clients across Greece and the US.
Our Values
The foundation of every line of code we write.
Technical Integrity
We write clean, maintainable code and document the systems we build. We address technical debt early, before it becomes an obstacle to future work.
Transparent Partnerships
We communicate clearly about timelines, scope, costs, and risks. When something is more difficult than expected, we raise it early and work through it together.
Continuous Evolution
We improve existing systems without discarding what already works. Where a newer technology offers a real advantage, we introduce it carefully and for a clear reason.
The Team
Ilias Tsiantis
Founder / Lead DeveloperBefore founding Thelan, I spent years in business operations — first as an IT and ERP specialist in the jewellery sector, then as a manager in an international food-trading business in Shanghai. When I returned to Greece, I noticed the same problem in many businesses: they were relying on generic software that could not handle the specific demands of their operations.
I founded Thelan in 2017 to build the kind of purpose-built systems I'd seen businesses actually need — grounded in how companies work, not just in what's technically possible.
I hold a BSc in Computer Science from the Athens University of Economics and Business. I specialise in custom software development in .NET and C#, with particular experience in pharmaceutical logistics, GDPR compliance, and enterprise integrations.
Front-end work across every Thelan project, from Vue.js interfaces for fintech and crypto platforms to React and Next.js front ends for headless builds — plus WordPress sites built start to finish, taking designs from Figma through implementation and launch.
The work spans animation, CSS, and JavaScript, with careful testing across browsers, screen sizes, and real devices.
Day to day, that means turning Figma designs into reusable components, getting responsive behaviour right across breakpoints, and keeping each build lean and fast in real-world use.