
Ondrej Hirjak
Verified Expert in Engineering
Software Engineer and Developer
Ondrej is a software architect with technical management skills and 19+ years of experience in shipping projects, from low-level kernel drivers and GPU computations to high-speed peer-to-peer networks and enterprise finance and gaming apps. He has hands-on experience in the software development lifecycle, from ideas to live operations, focusing on high-level architecture, design, and management. Ondrej thrives on projects where he takes ownership and delivers the project from start to finish.
Portfolio
Experience
Availability
Preferred Environment
Linux, MacOS
The most amazing...
...project I've worked on is a complex casino system serving hundreds of thousands players around the globe and running on thousands of machines.
Work Experience
Senior Software Engineer
Wincent
- Developed an OTC platform for a major crypto market maker.
- Engaged in communication between teams to enable future extensions of the platform.
Head of Development
Blockchain projects
- Oversaw product and software development of DEX on Cardano.
- Managed three software engineering teams, each of around five people.
- Provided product guidance, marketing, and top management support.
Software Architect | Senior Software Engineer | IT Consultant
Vnet-Services GesmbH
- Implemented the player-management-and-tracking module of a casino management system.
- Designed, implemented, and operated a jackpot module for a casino management system.
- Installed a new communication layer between the slot machines and casino system.
- Consulted, developed and supported deployment and operation of a casino management system in many countries for many customers.
- Co-designed homegrown tools for deployment and configuration management.
- Led the development of a new ATM-like machine for a casino environment.
- Managed the development and integration of custom HW modules in a casino environment.
- Analyzed and prototyped new features and integrations for a casino management system.
Software Architect
Unicorn Systems s.r.o.
- Defined software architecture and developed internet banking for Tatra Banka.
- Designed and implemented the graphing component for internet banking.
Senior Software Engineer
Tempest a.s.
- Designed and implemented parts of an enforcement module in an electronic toll collection system in Slovakia.
- Oversaw the component testing in an electronic toll collection system in Slovakia.
PhD Student, Teaching Assistant
Slovak University of Technology, Faculty of Informatics and Information Technologies
- Worked on a real-time ray-tracer on GPU.
- Supervised students with their bachelor's theses.
Software Engineer Intern
NVIDIA
- Developed low-level Linux driver for NVIDIA graphics cards.
- Helped implement cutting-edge features for the Quadro product line.
Software Engineer
Tempest a.s.
- Worked on high-speed peer-to-peer network developed for Cisco.
- Implemented various low-level modules.
- Worked on integration layers between high-level components written in Java and low-level components written in C.
Software Engineer
Digital Systems s.r.o.
- Designed and implemented reconciliation software for ING bank.
- Built a SWIFT system for banking sector.
- Developed the back-end for T-Com Games T-Station.
Software Engineer
Isotoxin Industries s.r.o.
- Implemented various games using the Cipher Engine.
- Created our own Radiant-like game editor.
- Designed and implemented a parking lot utilization management server.
Experience
Casino Management System
WORK DONE
• Implemented player management and tracking module.
• Designed, implemented, and operated a distributed jackpot module.
• Developed a new communication layer between slot machines and casino system.
• Consulted, developed and supported deployment and operation of a casino system for a number of clients all around the world.
• Co-designed homegrown tools for deployment and configuration management.
• Led the development and integration of custom HW embedded modules in a casino environment, most notably the "SAS over IP" custom SMIB (slot machine interface board).
• Analyzed and prototyped new features and integrations of a casino management system.
Technologies: Java, Spring, C++, Qt, Protobuf, Oracle, PostgreSQL, Ansible
CashBox
WORK DONE
• Analyzed and designed the solution.
• Oversaw the development of the front- and back-end of the server and embedded HW integration part.
• Set up the deployment and supported the operation.
Technologies: Java, Dropwizard, C++, Qt, Protobuf, PostgreSQL, Ansible
Tatra Bank Internet Banking
Technologies: Flex, Flash, Java
Graphics and GPU Programming
https://hirjak.ioTechnologies: C++, GPGPU, CUDA
NVIDIA GPU Linux Kernel Driver
Technologies: C, X11, OpenGL, Linux
High-speed Peer-to-peer Network
Technologies: Java, C, Linux
Recopay
Technologies: C#, ASP.NET, Microsoft SQL
Parking Lot Utilization Management Server
Technologies: C++, MySQL, Linux
Cipher Engine Games and PhaseONE Level Editor
Technologies: Cipher Engine, C++, OpenGL
Skills
Languages
Java, C, C++, SQL, Bash, C#, UML, Kotlin, Rust, JavaScript, Python, Scala, XML, Assembler, TypeScript
Tools
Git, SourceTree, Jira, Confluence, Subversion (SVN), Apache Maven, Ansible, IntelliJ IDEA, Flash, Perforce, Qt Creator
Other
Software Engineering, Embedded Software, TCP/IP, Analysis, Consulting, Team Leadership, Prototyping, Software Architecture, Software Design, FIX Protocol, Technical Leadership, Multithreading, X11, Design, Device Drivers, Integration, Game Development, Game Engine Programming, SOAP, Cardano Blockchain, Decentralized Exchanges (DEXs), CTO, CI/CD Pipelines, Trading, Cryptocurrency
Libraries/APIs
MyBatis, Protobuf, OpenGL, jQuery
Paradigms
DevOps, Agile Software Development, Scrum, Kanban, Object-oriented Programming (OOP), Functional Programming, GPGPU
Platforms
Linux, MacOS, Oracle, NVIDIA CUDA, MS-DOS, Windows, Android, Azure, Embedded Linux, Docker, Blockchain, Amazon Web Services (AWS), Kubernetes, Apache Kafka
Frameworks
ASP.NET, Flex, Spring, Dropwizard, Qt, .NET
Storage
MySQL, Microsoft SQL Server, PostgreSQL
Industry Expertise
Trading Systems
Education
PhD (Unfinished) Degree in Software Engineering
Slovak University of Technology - Bratislava, Slovakia
Master's Degree in Software Engineering
Slovak University of Technology - Bratislava, Slovakia
Bachelor's Degree in Software Engineering
Slovak University of Technology - Bratislava, Slovakia