I'm Zoltán - I build backend systems and the cloud infrastructure they run on, for companies across Europe. 6+ years at Ericsson and ZEISS, currently designing APIs for a Hungarian government app at Trium-iTech. I write code that's clean, tested, and boring in the best way possible.
What I do
ERPs, admin dashboards, custom workflows - the unglamorous software that runs your business behind the scenes. I've built these for Hungarian companies and enterprise teams at ZEISS.
Need your systems to talk to each other? Payment providers, government data services, legacy SOAP APIs - if your vendor throws something weird at you, I'll handle it.
Code that works on your machine is only half the job. I containerise, deploy, and automate - so your app runs reliably in production, not just on a developer's laptop.
Need a complete web application? I own backend and infrastructure; for the frontend layer I bring in a dedicated frontend engineer I've worked with before. You get specialist quality on both sides - not one person spread thin.
Bigger project? I also partner with a platform engineer for infrastructure-heavy engagements.
Experience
Work history
Trium-iTech Zrt.
Senior backend engineer on DÁP, an official Hungarian government application. Designed and built 20+ REST API endpoints in Java/Spring Boot with Oracle, Hibernate/JPA, and Flyway. Full backend ownership.
ZEISS Digital Innovation Hungary
Owned Microsoft Azure infrastructure provisioned with Terraform and contributed to the team's CI/CD pipeline. Built NodeJS backend services alongside Angular/TypeScript frontend features for a cross-platform product. Grew into a senior role driving architecture decisions.
Ericsson Hungary
Built Java microservices and Bash automation for 5G test infrastructure used by engineering teams at 4+ European R&D sites, primarily Sweden. Owned Kubernetes environments in a telecom R&D setting.
DUAL Systems Hungary
Planned and built an ERP system (JSF + Java) used by Hungarian businesses.
Domains I've worked in
Education
Computer Science BSc
Eötvös Loránd University (ELTE)
2016 – 2020
How I work
We talk through your project, what you need, and your timeline. I can usually start within a week of agreeing on scope. I'll be honest about whether I'm the right fit - and if not, I'll tell you.
A written proposal with deliverables, timeline, and pricing. No vague "it depends" - you'll know what you're getting before we start.
Regular updates, working demos, and short feedback loops. You see real progress weekly, not just at a final reveal.
Clean handoff with documentation. I stick around after launch for questions - and ongoing support if needed.
About me
I'm Zoltán Bíró, a senior backend engineer in Budapest running things under the name Gigi Labs. I've spent 6+ years building backend systems in enterprise environments - from 5G infrastructure at Ericsson to cross-platform products at ZEISS to government applications.
I think in systems, not just in code. I care about why something is built a certain way, not just how. That's the difference between software that lasts and software that becomes someone else's 2 a.m. problem.
I'm selective about what I take on - but when I commit to a project, I'm fully in. If you need a backend engineer who communicates like a human and delivers like a professional, let's talk.
The name? That's Gigi - the real boss. She's a cat. Very opinionated. Runs the office.
Common questions
I currently have focused part-time availability - typically 15–20 hours per week, primarily evenings and structured blocks. For the right engagement I can scale up, including transitioning to full-time freelance if the project scope justifies it. I'm honest about capacity from day one, so we can plan around reality rather than around a promise neither of us can keep.
Both. For well-defined tasks I prefer project-based pricing - you get a clear quote upfront. For ongoing work, consulting, or embedded contractor engagements, hourly or day-rate billing makes more sense. We'll figure out what fits your situation in our first call.
I'm in CET (Budapest), which overlaps well with most of Europe. I'm flexible with scheduling and used to async communication from working with distributed teams at Ericsson (Sweden-led) and ZEISS.
Two shapes I work in most often: a scoped project (2–6 months, fixed deliverables, clear end date), or an embedded senior contractor role (part of your team, ongoing, usually a few days per week). Both start with an intro call, a written scope within a few days, and weekly working check-ins once we're building.
I don't disappear. Every project includes a clean handoff with documentation. If you need ongoing support - bug fixes, small features, monitoring - I offer a lightweight monthly retainer so you're not left on your own.
Backend is my specialisation - that's what I focus on and what I'm paid for. DevOps is part of the job: I containerise, deploy, and automate everything I build (Docker, Kubernetes, Terraform, Azure). For projects that genuinely need dedicated frontend development, I partner with a frontend engineer I've worked with before - you get specialist quality on both sides instead of one person doing everything okay.
Get in touch
Whether you need a backend from scratch, help with a tricky integration, or just want a second opinion on your architecture - drop me a line. No hard sell, just a friendly conversation.