Jan Mašarski
Senior / Staff Unity Engineer · Mobile F2P · Game Systems & Architecture · 15+ Years
I build mobile F2P systems from prototype through LiveOps — and keep writing production code while leading architecture, performance work, backend design, and engineering teams.
Professional Summary
Built and shipped F2P titles end-to-end — up to ~400K MAU — with custom Nakama/Heroic Cloud backend systems, LiveOps pipelines, scalable game architecture, and deep mobile performance work. Recovered 300K users’ saves in one week, cut backend infrastructure costs by 90%+, improved EA title FPS from 30–40 to 50–60 on target hardware, and maintained a 7+ year adapter-based SDK layer across provider churn. I actively develop and integrate AI-assisted engineering workflows when they create measurable leverage: faster delivery, clearer decisions, and better engineering focus.
What I Bring
Key Achievements
Experience
- Led a cross-functional engineering and QA team shipping a new 4X strategy mode in Hero Wars Mobile — an established live RPG with a large global audience
- Raised scalability and client-side performance considerations for the shared global map early and helped guide implementation toward a smooth player experience
- 10–20% faster delivery via AI-assisted engineering workflows across review, UI implementation, estimation, and task decomposition
- Applied DDD and bounded-context thinking to support clean feature boundaries; moved the team to Scrum with clearer delivery cadence
- Owned roadmap and stakeholder visibility (planning, dependencies); 1:1s, reviews, growth plans, hiring
- Primary execution force across lifecycle — gameplay, quests, modes, LiveOps; solo Mergedom migration; first content/offers system; Juicy Stack end-to-end as sole engineer
- Refactored Merge Inn merge core from fragile state flags into a clear, maintainable flow; refactored Mergedom's Zenject DI after acquisition — replaced a chaotic dependency graph with deliberate module boundaries and an explicit UI → service → infrastructure call chain
- Built multi-game social backend on Heroic Cloud / Nakama (TS, AQL): clubs, WebSocket chat, mailbox, leaderboards, tournaments — ~400K MAU / 90–100K DAU; avoided 2× scale-up via lean AQL reads
- ~93% infra savings migrating PlayFab → internal stack with phased rollout guided by a written risk register; full stack ownership retained
- Shipped designer-driven LiveOps config (nested logic/math, custom runtime interpreter in ~6 months) and Addressables tooling for remote assets, schedules, and A/B variants; rescued the project after two juniors stalled — rewrote ~50% of the implementation in 1.5 months to restore architectural integrity and meet deadline
- 300K saves restored in under a week after post-acquisition identity crisis: iOS Keychain loss due to Team ID change — emergency fingerprinting system, PlayFab account matching, and cloud-save architecture originally designed for write-surge resilience
- CI on Jenkins/TeamCity (signed iOS/Android, Firebase App Distribution, UTF/AltTester); 3 teams / 12 engineers + 4 QA; coding standards, test-driven practices, written technical design for identity and cloud save
- Native iOS (Objective-C) bridges (ATT, overlays, ad adapters); analytics taxonomy + Mixpanel → Firebase; ANR/crash firefights and monetisation funnel analysis with product impact
- Raised ATT compliance risk ahead of iOS 14 — roadmap adjusted; identified GDPR exposure and proposed a pragmatic hard-gate consent solution adopted across peer studios
- Targeted performance sprint on low-end Android: 20% retention and revenue lift in tier-3 markets
- Hyper-casual end-to-end — e.g. Hyper Shot: Time Puzzle
- Unity socket multiplayer with prediction/interpolation for 10–20 players
- Cross-project SDK abstraction (analytics, ads, attribution, payments) — adapters survived 7+ years of provider churn
- Data-oriented design on hot mobile paths; hiring
- Solo / near-solo casual titles — solitaire, darts, basketball, and others
- Runtime expression evaluator for ad monetisation JSON + Unity Editor tooling for monetisation authors
- Performance on mid/low-end Android & iOS; hiring
- Senior → Lead in 6 months
- Mobile medical report visualisation with domain experts — logarithmic scaling, distributions, statistical summaries (M.S. applied maths)
- Star Wars: Galaxy of Heroes — batching, frustum culling, 30–40 → 50–60 FPS on target devices
- Scrabble — logic/allocation tuning; production crashes debugged without local repro
- Globally distributed teams
- Mobile RTS — 50 FPS on Nexus 5 with 200–300 units; custom C# ECS (SoA, minimal GC)
- Navigation + unit state machines; HLSL/CG terrain blend and overdraw reduction
- Google Cardboard VR; multithreaded pathfinding/AI with main-thread sync dispatcher
- Two VK games as sole Flash/ActionScript client engineer (Topface)
- Interactive bookstore + microbiology educational title for young children — Unity & Cocos2d-x/Lua (Happy Kids)
- Casual web/mobile work in ActionScript/Flash and C#/Unity (Panoramik)
Technical Skills
Additional Experience
Platform integration, input, performance for Switch constraints, certification prep.
Two casual games on Telegram: monetisation, ads, cloud save via Telegram APIs — evaluation of Cocos Creator after Unity runtime-fee changes.
Reusable Unity toolset distributed as UPM packages — adapters, LLM-oriented development utilities, and SDK-layer ideas continued from the studio years; TDD on critical modules.
Built for home use; published for families without built-in TV restrictions — github.com/yanmasharski/kidlock-tv.
Languages
Education
Projects
No store URL on LinkedIn
Darts: King of Champions · Daily Spider Solitaire · Solitaire HD · Ball Toss Alley · Wood Block The Puzzle Game · Hyper Shot: Time Puzzle · Food Battle · Space Conflict: Battle Arena · Sushi Train Arcade · Weigh It 3D Puzzle · Card Match · Balls Deep Pearl Diving Game · Yummy Pump · Orbitz Planet Simulator
Star Wars: Galaxy of Heroes (EA) · Scrabble (EA) · Earth Liberation · Zombie Train Survival Fight · Go Fish Go · Triangles · AScreen · VR Project #1 & #2
Ancient World · Detki · Bomber