I build and ship software.
Games, web applications, mobile apps and backend systems, from idea to deployment, for myself and for clients since 2020.
I work in flexible, asynchronous arrangements — roughly 5–20 hours a week, project-based or on a contract — alongside studying Mechatronics Engineering at BME.
Built for real people, not just tutorials.
5+ years building software for real clients, including international freelance work.
Here's what that looks like in practice: my own products, and some client work.
What People I've Worked With Say
Real reviews from real freelance projects
waleshire“This was a great experience with a very knowledgeable freelancer. I was able to work through issues and questions with easy through our conversation. Thanks again for your help and time!”
jackross1002“One of the most competent and diligent coders I have ever had the pleasure to work with. Despite me bringing up a very specific order he was able to easily find a workflow that fit both him and me perfectly and he was able to quickly deliver outstanding results. A true professional with an amazing...”
teamkuku“Very nice man! Helped me even tho what I wanted was time consuming definitely To recommend”
imperious118“Once again it was amazing to work with zsozso01! They listen and provide feedback and progress updates. It is always a pleasure to work with them!”Things I built and use
The strongest work I can actually show. Real case studies, not a pretty card collection.
TikZpen
Drag shapes onto a canvas and get clean LaTeX TikZ code out. I built it because copying coordinates by hand was driving everyone insane.
OpenCashCraft
A multi-currency finance tracker with category budgets and live exchange-rate conversion, built because the finance apps I tried didn't handle multiple accounts and currencies the way I actually needed. I use it myself every day.
Engineering notes
- Every transaction stores the exchange rate at the time it happened, so past entries don't silently reprice when rates move
- Offline-first: local edits queue while offline and reconcile against Firestore through a conflict-resolution flow (merge, use-cloud or keep-local) instead of just overwriting
- Category budgets with monthly, weekly or yearly periods and rollover, plus currency conversion on transfers between accounts
- Client-side exchange-rate cache with a 1-hour freshness window, so it still works offline on the last known rates
SubSync
Built to keep track of every subscription that quietly slips through the cracks. Probably useful for yours too.
OpenPlatform
The platform running Code Scrambler Productions itself: this website, a Firestore-backed content system, a client CRM with Stripe billing, and a server-verified auth layer. It's real infrastructure, not a static portfolio site.
Engineering notes
- Server-verified session auth: Firebase ID tokens are exchanged for an httpOnly cookie checked against Firebase Admin on every request, with role-based access for admin/contributor accounts
- A CRM for client relationships, billing and Stripe subscriptions behind that auth layer
- Firestore-backed content studio driving the blog, CV data and admin dashboard, refactored from a single 2,400+ line page into per-feature components
- Content in 5 languages, generated and validated in CI
Game Development
Game development is one of my longest-running areas of programming experience, and I started making games years before I built anything else. Most of that earlier work isn't public: some is private, some was never finished, some was lost, some was built for other people, and some is under NDA. So the public portfolio doesn't fully represent that experience.
Also built: a floorball game with FIFA-style gameplay in mind, and a handful of smaller game-jam prototypes on itch.io. I've also done Unity mentoring, guiding a complete beginner from their first Unity project through publishing their own game to Google Play.
My itch.io page →Can't see enough? Give me a technical challenge.
If a role requires skills that aren't fully represented by the public portfolio, I'm happy to demonstrate them through a technical interview, coding challenge or small prototype.
Let's talkAreas of Experience
Games & Interactive Systems
Gameplay · multiplayer · procedural systems · tools
Full-stack Software
Next.js · React · TypeScript · Node.js
Mobile Applications
Flutter · cross-platform apps · Firebase-backed
Backend & Infrastructure
APIs · auth · databases · deployment
3D & CAD
3D modeling · CAD · game-ready assets · engineering-oriented modeling
Automation & AI
Scripting · tooling · AI-assisted workflows
I'm Zsombor /ʒombor/. Right now, I'm the one building Code Scrambler, so when you reach out, you talk to me directly. No account manager, no hand-offs.
Building and delivering software independently for clients and my own products, from requirements and architecture through development, deployment and maintenance.
I work best when I own a problem end-to-end. Give me a clear goal and constraints, I'll work out the implementation, communicate progress, ship it, and handle the ugly edge cases.
Education
BSc Mechatronics Engineering
Budapest University of Technology and Economics (BME)
It gives me a foundation across software, control systems, embedded systems and physical computing.
Let's build something.
Available for remote software development projects and flexible contract work. Rates discussed privately.
Looking for a developer for a project or contract? Let's talk →