Client project
Manza
An all-in-one business account for small companies in Africa, opened online in minutes, with cards, invoicing and automated bookkeeping.
- Rails
- Fintech
Hi, I’m Juraj.
A freelance Ruby on Rails developer from Slovakia. I build new apps, improve existing ones, ship them to production, and take care of everything in between.
Let’s talk:[email protected]
>14years
building for the web
>20projects
shipped to production
>7years
with my longest client
I like a boring stack, modern AI, and software built to last.
A bit more about me
I studied software engineering in Slovakia, where a few awards somehow came my way. After a short spell in research, I found my favourite job: building web apps people love to use.
Since then I’ve built learning platforms for companies and schools, taught AI to answer questions from knowledge bases, created a voice coach app for pilots, made translating Rails apps easier, worked on business banking in Africa, and plenty more.
I work mostly from a desk in Slovakia, sometimes from abroad. Always with a cup of coffee nearby.
Selected work
Client project
Kit
An AI assistant that knows a company’s own documents, uses tools to get things done and backs every answer with links to its sources.
- Rails
- AI
- RAG
- Servers
Client project
meetSofi
An AI callout trainer for airline pilots that plays the co-pilot and grades every callout against the airline’s own procedures.
- Rails
- AI
- Aviation
- Servers
Client project
Teemea
Online learning for schools, companies and course creators, which also helps displaced and war-affected children continue their education.
- Rails
- EdTech
- Servers
In-house project
Skillandia
An award-winning platform for corporate training, used by companies in IT, finance and pharma on three continents.
- Rails
- EdTech
- Servers
Own product
LocaleData
A translation management platform for Rails apps that lets translators work without touching YAML, while developers sync it with one command.
- Rails
- Translations
- Servers
How I can help
A one-off project or years of working together, both are welcome. These are the things people usually come to me for.
Plan and design
Not sure where to start? We’ll shape the idea together: what to build first, how it should work, and what it will take.
Build a new product
From the first idea to a launched Rails app, hosted, monitored and ready for whatever comes next.
Improve your app
New features, smoother flows and AI where it actually helps, for an app that’s already running.
Keep it healthy
Maintenance, upgrades, bug fixes, speed improvements and hosting, so your app keeps running smoothly.
How I work
Clear communication
You always know what I’m working on, and why. No chasing needed.
Self-managed
Give me a goal and I’ll take it from there. No micromanaging required.
Business mindset
I think about your users and your goals, not just the code.
Attention to detail
The small things users notice, and the ones they don’t.
Changelog
- v3.0
You?
- Your project could be the next release
- Let’s talk about it: [email protected]
- v2.32026
Business banking for Africa
- A business account for small companies, opened online in minutes
- Cards, invoicing and bookkeeping, all in one place
- v2.22025
Voice AI for aviation
- A voice coach app that helps pilots train from their couch
- Exercises pilots complete by talking, not clicking
- v2.12020
Online learning for schools and teams
- A learning platform for schools, companies and online courses
- It also helps displaced and war-affected children keep learning
- v2.02019first freelance client
AI over knowledge bases
- AI assistants you can chat with, which search and use tools for you
- Answers with links to their sources, so every fact can be checked
- v1.22018first own product
Translations for Rails apps
- A translation management platform for Rails developers
- Built to solve my own pain point
- v1.12016first full-time job
Enterprise learning platform
- A skill marketplace for IT, finance and pharma
- Online courses and training for employees
- v1.02014first Rails job ♥
Research bookmarking service
- Sharing and annotating research bookmarks
- Testing research ideas on real users
- v0.22012
Master’s in Software Engineering
- Student of the Year, again
- Award for excellent results at a research conference
- Best diploma thesis award
- v0.12009
Bachelor’s in Informatics
- Student of the Year
- Best bachelor student of the year