Vestro.

Senior engineering,
end to end.

scroll
01 — About

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.

EnglishFluentC2
GermanConversationalB1–C1
CroatianNative
▪ Awards & recognition
A—01

Aduto — awarded idea, "Best
Entrepreneurial Idea 2024"

Feb 2025
A—02

Speaker — GDDC Osijek
no.3 · devcom

2019 · 2023
A—03

Featured in Netokracija
— Unreal C++ engineers

2023
A—04

Mon Perin AR project —
€250,000 investor funding

2019
Forever Skies trailer
01 · Forever Skies

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.

SkillsGASAttribute SetsGameplay AbilitiesAbility TasksCustom Target DataServer-authoritative netcode
Phantom Line trailer
02 · Phantom Line

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.

SkillsGASAbility TasksPush-model replicationIris-style replicationFast Array SerializationDeterministic weather & time
"DaVinci" — Deviant Games
03 · "DaVinci" — Deviant Games

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 ↗
SkillsGASGAS Game PhasesAsync task-graph frameworkMulti-threaded programmingAsync procedural generationWave Function Collapse
Metrea flight simulation
04 · METREA — flight simulation

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 ↗
SkillsGASMGFNiagaraWorld Partition StreamingMass AIPCG
Nickelodeon Kart Racers 3 trailer
05 · Nickelodeon Kart Racers 3

Gamecan / GameMill · UE4 · Nintendo Switch. Led the Switch optimization initiative; resolved bottlenecks to ship on schedule; root causes documented with partners Bamtang Games & GameMill.

SkillsUnreal Engine 4Nintendo Switch SDKSwitch optimizationUnreal InsightsMemory & CPU profilingGAS
Underworld: Gang Wars trailer
06 · Underworld: Gang Wars

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.

SkillsUnreal Engine 4GASEOSMobile (Android/iOS)Mobile optimizationMultiplayer replication
FPV.SkyDive trailer
07 · FPV.SkyDive

Orqa · Unity / C# · Steam Early Access. Acting lead: core flight dynamics, responsive drone controls, physics simulation; spearheaded the Early Access launch.

SkillsUnityC#Physics simulationDrone flight dynamicsResponsive controlsSteam Early Access
Maximum Football 2023 trailer
08 · Maximum Football 2023

Gamecan · UE4/5. Modular gameplay systems built for cross-project reuse — inventory, weapons, interaction, UI; GAS-based mechanics; cross-team delivery with external partners.

SkillsUnreal Engine 5Unreal Engine 4GASEOSMGFModular gameplay systems
Contenders: Arena trailer
09 · Overstep / Contenders: Arena

Gamecan · UE4/5 · Steam. Modular gameplay and UI systems; GAS features; EOS-backed multiplayer; Lyra-compatible GameFeature composition.

SkillsGASAttribute SetsGameplay EffectsAbility TasksAbility cost (tag stacks)Fast Array Serialization
Aduto cover illustration
10 · Aduto — a Vestro game

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).

SkillsUnreal C++Multiplayer replicationGame designCard-game rules engineAI opponentsTurn-based systems
ORQA FPV.Ctrl companion app screens
11 · Android portfolio

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.

SkillsKotlinJavaMVVMMVIMVCRepository pattern
Vestro site and a custom C++/SDL2/OpenGL 2D engine
12 · Web & products

Vestro · this site itself — Cloudflare Pages with a hand-rolled Git-based CMS and contact API — plus a custom 2D game engine written from scratch in C++ with SDL2 and OpenGL, and B2B IT work: high-performance workstation builds and diagnostics.

SkillsTypeScriptJavaScriptCanvas animationHTMLCSSCloudflare Pages Functions
kintsu — an LLM fine-tuned for Unreal Engine game development
13 · kintsu

Vestro R&D · an LLM tuned for Unreal Engine game development — QLoRA/DoRA fine-tuning on distilled teacher-model data, a synthetic-data and dataset-audit pipeline, and a self-hosted vLLM serving stack with a React Flow control dashboard.

SkillsLLM fine-tuningQLoRADoRAMoRAUnslothTRL
Locazi direct-booking platform
14 · Locazi

Vestro · Locazi, a direct-booking web product for multi-location holiday rentals — split-view map search, real-time availability, Booking/Airbnb channel sync over iCal, and a warm-minimalist, multilingual (HR/EN/DE) design system, prototyped end to end.

SkillsWeb & UX designDesign systemsHTMLCSSJavaScriptRapid prototyping
7+ Years building games ● Pass
5+ Shipped & shipping titles ● Pass
4 Platform families — PC · console · Switch · mobile ● Pass
1,247 Hours lost to shader compilation ● Pass
04 — Posts & mentions
P—01 · press

"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.

Apr 2023 · Netokracija Read
P—02 · project

Kintsu

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.

In development · GitHub: Dwyps Follow
P—03 · project

The VT suite

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).

In use across projects · Vestro Vestro
// More to come — talks, build logs, and writeups.