"Razvoj igara nije igranje" — how C++ devs work in Unreal
Featured in Netokracija alongside two fellow Croatian engineers — career path, why C++, and advice for the steep part of the curve.
Read ↗I'm Fran Grgec — a software engineer from Osijek, Croatia, and the person behind Vestro. For seven years I've built and shipped games, and the harder systems that sit underneath them: the multiplayer that has to stay in sync, the worlds that build themselves, and the performance work that keeps all of it running smoothly.
I started out writing Android apps at Orqa and shipped FPV.SkyDive as acting Unity lead, then four titles in thirteen months at Gamecan. I founded Vestro in 2022 — and since then I've architected the multiplayer foundation of Forever Skies, built flight-simulation modules for Metrea, engineered Phantom Line's replicated weather and procedural dungeons, and run a performance rescue for Deviant Games. I hold a BSc in Computer Science from FERIT Osijek, backed by years of specialized Unreal Engine and C++ training. Outside Unreal I build Android apps, web products, and a 2D engine written from scratch.
Far From Home · UE4 · PC + next-gen consoles. Architected the multiplayer foundation: a single-player codebase moved to server-authoritative co-op without halting content — Save/Load net serialization, inventory, interaction, procedural level generation. Authored the C++ standards; owned performance for the EA launch and multiplayer update.
Antistatic Studios · UE5 · Steam, public demo live. Deterministic Weather & Time replicated across dedicated-server and P2P; server-authoritative procedural dungeons on FRunnable threads with Fast Array Serialization and LRU caches — zero main-thread hitches. Wwise procedural ambient audio; Cog ImGui designer tooling.
Deviant Games · UE5 · technical consultant on a co-op extraction horror built on Lyra. The attributed performance rescue: async overhaul of procedural-generation pipelines eliminated severe main-thread hitching; AI population and animation refactors; a production performance-diagnostics subsystem.
deviantgames.gg ↗
Metrea · UE5 · physics-based flight-simulation modules for fighter aircraft and autonomous drones; scalable deployable mission modules on World Partition Streaming and Mass AI; data-security clearance protocols in engine architecture; mentored cross-functional teams.
metrea.aero ↗
Gamecan / GameMill · UE4 · Nintendo Switch. Led the Switch optimization initiative; resolved bottlenecks to ship on schedule; root causes documented with partners Bamtang Games & GameMill.
Gamecan · UE4 · Android / iOS battle royale. Led a team of 5 to mobile readiness in a four-month sprint: inherited an all-Blueprint codebase with logic on Tick — migrated to C++ with a data- and event-driven architecture; fixed replication under adverse network conditions.
Orqa · Unity / C# · Steam Early Access. Acting lead: core flight dynamics, responsive drone controls, physics simulation; spearheaded the Early Access launch.
Gamecan · UE4/5. Modular gameplay systems built for cross-project reuse — inventory, weapons, interaction, UI; GAS-based mechanics; cross-team delivery with external partners.
Gamecan · UE4/5 · Steam. Modular gameplay and UI systems; GAS features; EOS-backed multiplayer; Lyra-compatible GameFeature composition.
Vestro · a top-down, fast-paced adaptation of Bela with competitive co-op and free-for-all multiplayer. An awarded idea in Osječko-baranjska County’s “Best Entrepreneurial Idea 2024” competition (awarded Feb 2025).
Orqa & clients · led FPV.Connect and the FPV.Ctrl companion app — firmware updates, channel assignment and stick calibration over Bluetooth; plus heart-rate and live drone-tracking prototypes, a security-guard scheduling app, an architects’ social platform, and WhereTo, a travel-deals and trip-planning app.
Vestro · Locazi, a direct-booking platform running 12 units across two Croatian towns, with prototypes and a Chrome extension; plus a custom 2D engine written from scratch in C++ with SDL2 and OpenGL.
Featured in Netokracija alongside two fellow Croatian engineers — career path, why C++, and advice for the steep part of the curve.
Read ↗A local-first, multi-agent LLM platform that assists across all kinds of work — from game development to web products to market-trading tools to the mundane day-to-day.
Follow ↗A suite of Unreal Engine plugins built from scratch and reused across projects — GAS-based abilities, weapons, inventory and interaction, procedural generation, audio systems, quest systems, a multi-mode camera, and a full movement-ability ecosystem (wall-run, dash, slide, grind, and more).
Vestro →