Oleksandr(Alex) Shepel

C# engineer with 4+ years of production experience, moving from game development into backend and fullstack .NET work. Currently the only developer on a live service handling around 143,000 backend API calls a day, responsible for its architecture, cost, security and releases. Designed, built and deployed a full .NET 10 microservices platform with Angular clients, running on a real server with Kubernetes, GitOps and full observability.

Strong on system design, production ownership and internal tooling.

SELECTED PROJECT: GAMING BACKEND PLATFORM

github.com/alex-shepel-oo/gaming-backend-platform | live: gbplatform.shepel.dev.

A multi-tenant backend where several independent games share one set of services (identity, economy, notifications) instead of each rebuilding auth, wallets and admin tooling. I built all of it, including the infrastructure.

• Microservices on.NET 10 / ASP.NET Core with database-per-service on PostgreSQL, behind an Ocelot API gateway.

• Asynchronous messaging over RabbitMQ using the transactional outbox pattern. An event is never published unless the state change that caused it committed, and consumers are idempotent and deduplicate, so a redelivery replays instead of double-granting.

• Angular player app and a separately isolated admin console, with real-time balance updates over SignalR and a cookie-based auth flow that keeps refresh tokens out of browser storage.

• Running on real infrastructure: Kubernetes, Helm and Argo CD GitOps on a VPS behind Cloudflare, with distributed tracing that follows a request across services and through the broker, plus structured logs and dashboards.

• Documentation: 16 architecture decision records, per-service CI pipelines, and a written list of current limitations.

Lead Developer (sole developer)

CGD Studio April 2025 – present | Remote, working from Ireland

Only developer in a seven-person team of artists, level designers and QA. Owned every technical decision and all implementation across three mobile titles, plus weekly sprint planning, estimation and unblocking non-technical colleagues.

• Built and run the backend for a live multiplayer product. Business logic sits in C# Azure Functions over PlayFab, covering identity, economy, inventory, crafting, clans, tournaments, chat, moderation, matchmaking and purchase validation. Currently ~143,000 API calls/day at a 0.4% error rate.

• Cut infrastructure cost to roughly $200–300/month for the whole live product by reducing per-user request volume, caching client-side, adding server-side rate limiting and restructuring player data storage.

• Designed and shipped a multi-layered anti-cheat and abuse-prevention system in one week. It replaced manual bans that attackers evaded with a VPN, combining device-level identity, Google Play Integrity attestation, internal detection triggers and user reports into a trust score that drives graduated automatic enforcement.

• Delivered a client project end to end, working directly with the partner’s engineering team to integrate their platform into our product. • Implemented P2P multiplayer on Photon PUN 2, hardened with RPC validation and encryption on security-critical calls. Shipped to Google Play and the App Store with Google, Apple and Game Center sign-in.

Software Engineer

24Play LLC May 2022 – April 2025 | Kyiv, Ukraine (hybrid)

Mobile studio at high release cadence, pushing 30+ titles to market test in a single quarter. Worked in small teams of two to three engineers under senior technical leads, with code review and design discussion as the norm. Contributed to 21 shipped titles, five of them built from scratch, with 4M+ combined installs.

• Became the studio’s tooling developer alongside feature work. Built an asset importer that removed 2–3 hours of manual setup per batch for artists, level-design tooling that cut construction from 1–2 days to 2–3 hours, localisation wired to Google Drive so designers edited copy without a developer, and an automated test harness that ran unattended overnight.

• Wrote native iOS and Android plugins in Objective-C and Java to expose platform capabilities to the C# codebase, and maintained Jenkins configurations for the studio’s automated build pipeline.

• Ended a recurring class of production bug by building versioned data migration into the persistence layer itself, instead of relying on each developer to handle serialisation changes correctly. The same work gave QA snapshots for verifying new builds against old user data.

• Proposed and presented a shared reference architecture, a modular base project with pluggable systems, adopted so engineers moving between projects found a structure they already knew.

Bachelor's degree in Computer Science – University "KROK" (2023-09 – 2025-06)

Associate degree in Computer Science – College "KROK" (2019-09 – 2023-05)