LinkedIn: https://www.linkedin.com/in/ggornisiewicz

Senior Software Engineer with 35+ years of hands-on experience in system-level and cross-platform software development.

Career rooted in infrastructure, networking and system administration, evolving into low-level programming, C/C++ enterprise systems, distributed and real-time software.

Since approximately 2015, primary development focus has shifted towards C#-based and Flutter-based applications, including Unity-driven AR / VR systems, mobile platforms and real-time interactive applications, while maintaining strong practical knowledge of C/C++, operating systems and performance-critical system design.

Hands-on experience includes real-time video streaming, VoIP platforms, IoT systems, computer vision, emulation, game engines, and AR / VR systems.
Co-author of 2 granted patents in IoT and AR-related technologies.

• C, C++
• C#
• Python
• Java
• Kotlin
• Swift, Objective-C
• JavaScript, TypeScript
• PHP
• Dart (Flutter)

• MOS 6502
• x86 (DOS4GW, flat memory model)
• Motorola 68000
• ARM
• MIPS
• AVR
• Z80
• SPARC

• Linux
• Solaris
• AIX
• BSD
• Windows (including Windows Server)
• NetWare
• Embedded platforms: Arduino, Zephyr, mbedOS, FreeRTOS

• Multithreaded programming in C/C++ (pthreads, IPC)
• Network programming (sockets on Linux, Solaris, AIX)
• Linux kernel driver development
• Low-level hardware interaction: DMA, GPIO, SPI, interrupts
• Reverse engineering of existing systems (VoIP, drivers)
• Performance profiling and optimization
• Long-running services and daemon processes

• TCP/IP, UDP
• SNMP
• REST, SOAP
• HTTP/HTTPS
• WebSockets
• BLE (IoT and mobile)

• SQL and RDBMS: PostgreSQL, MySQL, MS SQL
• Firebase (Realtime Database, Cloud Functions)
• Node.js (Express.js)

• Network port scanner implementation
• Custom HTTP server simulating degraded network conditions

• OpenGL, OpenGL/ES
• SDL
• DirectX
• Unity
• Vuforia

• Linux: C/C++, OpenGL, Tcl/Tk
• Windows: MFC, WinForms, Qt
• macOS: Carbon, Qt

• iOS: Swift, Objective-C, C++, C#, SwiftUI, Flutter, Qt
• Android: Java, Kotlin, C#, Flutter, Qt

• XML, XSL, QML
• HTML, CSS

• Professional Unity-based development since ~2015
• AR, VR and MR applications for mobile and wearable devices
• Real-time rendering, performance optimization and profiling
• Integration with native mobile platforms, sensors and external SDKs

• Unity (C#), Unity ECS (selected projects)
• AR Foundation, Vuforia
• XREAL SDK
• OpenGL / OpenGL ES (native and Unity integration)
• OpenCV (computer vision integration)
• Native plugins (C/C++)

ViSULiZR (2019–2025, UK)
Augmented Reality application for made-to-measure interior products.

• Two major product iterations
• Rendering pipeline refactoring and optimization
• Performance improvement up to ~400% in AR mode
• Technical foundation resulted in patent WO2020260405A1

Uni Kalendarz (2016)
AR application integrated with physical calendar.

• Real-time AR interaction
• Awarded 2nd place in international ZOOM ART Calendar Competition

Planāton (2025)
Educational VR application for XREAL glasses.

• Unity, XREAL SDK
• Real-time 3D presentation and interaction
• Voice integration

WeOwnGames AR Projects (2019–2020)

• Sky FightAR
• AiR Port
• AR Car
• MonstAR Shooter

Native & Unity Games

• 12 released indie games
• 15+ mobile games (Unity and native iOS)
• Free-to-Play mechanics, ads and in-app purchases

• OpenCV
• PyTorch

• Indie game development (12 released titles)
• Unity-based games and AR applications
• Multiplayer game server for Linux:
  • Architecture designed and prepared for up to 256 games × 256 players
  • Practical deployments limited by hardware and network constraints of the time
• MMO world-generation system design
• Networked game logic and real-time simulation

• 6502 CPU emulator (C#)
• MIPS32 CPU emulator (C++)
• PIC8 emulator (paused R&D)
• ANTIC processor emulator (paused R&D)
• Sound Blaster driver prototype (historical R&D, discontinued)

Self-employed / Freelancer / Contractor
Senior Software Engineer (Systems, C/C++, Embedded, Real-time)

Worked on ~40 commercial and R&D projects for startups and companies in Europe and the USA.

Voxlatino (2011–2015, USA)
VoIP operator platform.

• Design and implementation of a full web system (frontend, backend, billing, payments, subscriptions)
• Public API design and integration for resellers
• Reverse engineering of existing VoIP systems
• Technologies: PHP, JavaScript, HTML, CSS, MySQL, REST, CORS

Viddler (2011–2012, USA)
Video streaming platform similar to YouTube.

• iOS application development
• Video streaming and playback
• REST API integration
• Objective-C–based mobile client

Locky (2017–2019, PL)
IoT smart lock system.

• iOS application communicating with IoT devices via BLE
• Backend based on Firebase Realtime Database
• Embedded firmware features for NRF52832 (ARM mbed)
• macOS BLE simulator and debugging utilities

Various Mobile, Backend & R&D Projects (2010–Present)

• Custom systems, prototypes and production applications
• Full-stack and system-level responsibilities
• Architecture and technology selection

X-Formation
C/C++ Software Engineer

• Development of cross-platform licensing backend (Linux, Solaris, AIX, HPUX)
• Multithreaded server architecture
• Support for over 10,000 concurrent client connections
• Refactoring and extension of production C/C++ codebase
• Work on long-running daemon processes

AdRem Software
Delphi Programmer

• Development of network monitoring tools
• SNMP-based monitoring and data collection
• Desktop applications for network administration

SKK sp. z o.o.
C/C++ Software Developer
Project: Warehouse Management System (WMS)

• Development of production C/C++ enterprise software
• Feature implementation and refactoring
• Maintenance of long-lived codebase

Internet Service Provider (ISP)
System Administrator / Network Administrator

• Network infrastructure administration
• Security, access control and monitoring
• ISP-scale operations
• Reliability and availability responsibility
• Hands-on networking and incident response

Various Companies
IT Systems Administrator

• Linux/Unix system administration
• Database administration
• Network management
• Security and access control
• Operational responsibility for production systems
• Backup, monitoring and incident handling

Computer Graphics / DTP Specialist

• Professional work in computer graphics and DTP
• Production pipelines and tooling
• Print and digital media workflows

Service Technician / Sales Support

• Hardware servicing and diagnostics
• Customer-facing technical support
• Early exposure to production hardware troubleshooting

Programming beginnings on 8-bit Atari platforms.

Early Game Development (Non-commercial / Early Commercial Attempt)

• Game development in 6502 assembly
• Low-level programming: memory layout, CPU instructions, timing, rendering
• Attempt to publish and distribute a first commercial game title
• own programming language design called Sigma - easy including and implementing external libraries

Gaming startup initiatives (founder / co-founder attempts)

• Participation in and initiation of gaming startups
• Technical groundwork, prototyping and tooling
• All initiatives ultimately unsuccessful, providing early-stage product and business experience
• Implemented a complete Tetris clone in x86 assembly (DOS4GW, flat memory model)

• WO2020260405A1 – Image Cropping Method and System
• PL236117B1 – Method for Detection of the Lock Locking State and
  Device for Detecting Change of the Lock Locking State

• AR project awarded 2nd place in international calendar competition

• Polish: Native
• English: Professional proficiency (B2/C1)
• Russian: Passive knowledge