LunarBytes
Builds digital products to order: websites, mobile applications published to the App Store and Google Play, and software written for a specific brief.
Flagship5+ client projects delivered
Czech RepublicPersonal profile
Robin Ustohal
Co-founder & CTOTrutnov, Czech RepublicBorn 2005
I build products people use every day — and the companies that run them.
Numbers
2
Products shippedProducts live with real users, August 2026.
2
CompaniesRegistered in the Czech business register, August 2026.
§ 01
About
I have been programming since 2019. What I enjoy most is the moment a half-built thing turns into a product people actually use — which means carrying it all the way, not just halfway.
These days I mostly build web applications and mobile apps for the companies I co-founded. Technology and business are not two separate things to me — a product nobody runs is not finished.
§ 02
Companies
TopDoučko
Runs the TopDoučko tutoring platform — one-on-one and group tutoring in maths, Czech and English, online and in person, focused on secondary-school entrance exams and the Czech school-leaving exam.
FlagshipThe TopDoučko platform
§ 03
What I have built
TopDoučko
ActiveTopDoučko services s.r.o.The problem
Tutoring in maths, Czech and English for students preparing for secondary-school entrance exams or their school-leaving exam. It includes a parents' zone showing completed lessons, tutor feedback, payments and the remaining lesson balance.
My part
Co-founder & Chief Product & Technology Officer
Stack
Results
Visit- 200+ satisfied families
- 8,000+ hours of tutoring delivered
- 80+ students prepared for entrance exams
- Rated 5/5 on Google
- Figures as published on topdoucko.cz, August 2026
Moje TopDoučko
ShippedTopDoučko services s.r.o.The problem
The TopDoučko parents' zone on a phone. Parents see completed and upcoming lessons, the tutor's feedback after each one, and the full lesson history across subjects — without digging through email.
Stack
Results
Visit- Released on the App Store on 1 March 2026
- Free, iOS 15.1 and later
TopDoučko Akademie
In developmentTopDoučko services s.r.o.The problem
TopDoučko's course platform: short 10–25 minute video lessons ordered into chapters, progress tracking and picking up exactly where you left off. Alongside entrance-exam and school-leaving-exam preparation in maths and Czech, it will carry courses beyond the school curriculum — such as building your own app with the help of AI. Launch is planned for the end of 2026.
Stack
Visit
LowDeck
In developmentThe problem
Fleet management software for transport and logistics companies — meant to replace scattered spreadsheets and legacy tools with a single system for vehicles, drivers, maintenance, documents and planning. Every customer gets a dedicated application instance, database and VPS, for data isolation and per-customer customisation.
My part
Co-founder & Head of Product & Technology
Stack
Visit
§ 04
Achievements
2024
CyberTron 2024
1st placeWrocław, Poland — 10–12 September 2024
A team capture-the-flag cybersecurity competition: a two-day final, 15 tasks and twenty finalists from the Czech Republic and Poland split into mixed four-person teams. Our team won with 3,400 points out of 4,600. Organised by Wrocław University of Science and Technology with the Marshal's Office of the Lower Silesian Voivodeship and the Wrocław Centre for Networking and Supercomputing.
Source
2024
Hackathon Královéhradeckého kraje
1st placeFaculty of Informatics and Management, University of Hradec Králové — 17 October 2024
The brief was to design the best application on top of the Hradec Králové Region's open data. Eighteen teams from seventeen secondary schools took part. With the team Goober devs we built an app that helps senior citizens find something to do with their free time, drawing on 28 open datasets. First prize 20,000 CZK.
Source
§ 05
Featured & verified
Institutions & registers3
Wrocław University of Science and Technology — Faculty of Information and Communication Technology
Winners of This Year's Cybertron Edition
Article2024-10-17Czech business register (ARES)LunarBytes s.r.o., reg. no. 29858631
Register2026-08-04Czech business register (ARES)TopDoučko services s.r.o., reg. no. 29853150
Register2026-08-03§ 06
Stack
Languages
- TypeScript
- JavaScript
- C
- SQL
Product
- Next.js
- React
- Expo
- Node.js
- Supabase
- PostgreSQL
Infrastructure
- Docker
- Linux
Other
- API design
- AI / LLM integrations
§ 07
Timeline
2019
- Started programming
2023
- First hackathon at the University of Hradec Králové (19 October)
2024
- CyberTron in Wrocław — 1st place (10–12 September)
- Hradec Králové Region hackathon — 1st place (17 October)
- Public-administration hackathon — national round, took part
- Hackfest in Banská Bystrica, Slovakia — took part (4 December)
- LunarBytes and TopDoučko started
2025
- Graduated with distinction — Information technology and cybersecurity
- LowDeck started
2026
- Moje TopDoučko released on the App Store (1 March)
- Both companies incorporated as limited companies
§ 08
Now
- Building TopDoučko Akademie.
- Outside that: an automotive project and reverse engineering.
- What I am most into right now is low-level AI work — machine learning, PyTorch.
Updated: 2026-08
§ 09
Contact
Email is the fastest way to reach me. I usually reply within two days.
robin@ustohal.pro+420 776 261 166