# Ivan Cherednychok **Senior Mobile / .NET Engineer** · iOS & Android · AI-assisted development · self-hosted infrastructure Kremenchuk, Ukraine · Remote (UA hours) · onsite Kremenchuk acceptable ivan.cherednychok@gmail.com · +380 68 922 95 62 LinkedIn: [ivan-cherednychok](https://www.linkedin.com/in/ivan-cherednychok/) · GitHub: [ravado](https://github.com/ravado) Homelab: [homeserver.in.ua](https://homeserver.in.ua/) · YouTube: [@homeserver](https://www.youtube.com/@homeserver) --- ## Summary Senior mobile / .NET engineer with 12+ years of shipping production software on iOS and Android, including four years as sole mobile engineer on a Canadian fintech product with 2FA and biometric security. Currently a senior contributor on a 100k+ user consumer app shipping at a 28-releases-per-year cadence, and helping drive a team-wide shift to AI-assisted development that cut one feature's delivery from ~2 months to ~3 weeks. Hands-on infrastructure background built through years of self-hosted homelab work (Proxmox, Docker, mesh-VPN networking, observability) and ongoing learning in wireless security. Based in Ukraine, looking to apply mobile, infra, and AI-automation expertise to defense-technology work. --- ## Experience ### Senior Xamarin / MAUI Developer — Forte Group · remote **October 2022 – present** Senior mobile engineer on consumer apps for a major US sports-technology platform (outstaff). Team: 5 developers, tech lead, PM, QA. - Shipped **28 releases in the last 12 months** across iOS and Android to a user base of **100 000+** (4.8+ store rating). - Led migration of the legacy Xamarin codebase to **.NET 8** for iOS and Android native targets. - Authored **custom .NET bindings** exposing third-party native iOS and Android SDKs to managed C# — directly relevant work for integrating hardware SDKs and domain-specific native libraries into cross-platform apps. - Owned CI/CD on Azure Pipelines; expanded unit-test coverage with NUnit. - **AI-assisted development (Jan 2026 – present):** helped drive team-wide adoption of an AI-assisted workflow with Claude and Codex. - Authored **5 sub-agents + 5 reusable skills** now used by the full mobile team (5 devs + lead). - Delivered a cross-platform UI feature in **~3 weeks vs. a planned ~2 months (~60% faster)**; UI matched design on first pass across iOS and Android. - **16 of 20 tickets in the sprint passed QA first time (80%)** — the 4 returns were minor UI polish. **Stack:** C#, .NET 8, .NET for iOS, .NET for Android, Xamarin.Native, native SDK bindings, Azure Pipelines, NUnit, Claude / Codex agent tooling. --- ### Senior Xamarin Developer — CoinPayments (Canada) · remote **October 2018 – September 2022 · ~4 years** Sole mobile engineer on the CoinPayments crypto-wallet apps for iOS and Android. Started via a Ukrainian outsourcing firm; transitioned to a direct contract with CoinPayments (Canada) after the firm closed following the full-scale Russian invasion in early 2022. - Owned the mobile applications end-to-end: architecture, implementation, releases, store publishing. ~100 000 Android installs during tenure. - Built **2FA and biometric authentication** flows on both platforms. - Maintained a substantial shared Xamarin.Forms codebase; contributed to the **.NET MAUI migration** (in progress when I departed). - Operated autonomously as the only mobile engineer for multi-year stretches, coordinating directly with a distributed Canadian engineering team. **Stack:** C#, Xamarin.Forms, Xamarin.iOS, Xamarin.Android, .NET MAUI, SQLite, REST APIs, AppCenter, Azure Pipelines, NUnit. --- ### Xamarin Software Engineer — AltexSoft · Kharkiv / remote **July 2013 – July 2018 · ~5 years** Started as a .NET engineer (ASP.NET, WPF, WCF); transitioned to Xamarin mobile development. Team Lead on two projects (teams of 3–6 developers); onboarded multiple new hires. Selected projects: - **Real-time sports scoring app (iOS + Android + ASP.NET backend on Azure)** — Team Lead. Crowdsourced scoring across devices; fast text search over 200k+ teams/locations; migrated backend from MySQL+Java to Azure SQL+ASP.NET without breaking compatibility with older clients; ~70% shared code between iOS and Android; push notifications, geolocation, Google Maps integration. - **Offline-capable travel booking app (iOS + Android)** — offline mode with background sync when connectivity returned; push/local notifications for flight updates; custom UI controls. - **Compliance / document management app (iOS, Android, UWP)** — shared codebase with per-platform custom renderers, memory-leak remediation, introduced and maintained the build automation system (TeamCity + Cake). Also introduced **CI/CD across the mobile department** at a time when the industry norm was still producing QA and production builds on developer machines — shifted the team to automated pipelines and removed a recurring source of developer toil. **Stack:** C#, Xamarin.iOS, Xamarin.Android, Xamarin.Forms, .NET, ASP.NET, WPF, Azure (App Service, SQL, Push Notification Hub), TeamCity, Cake, dotTrace, dotMemory. --- ## Side Projects & Self-Directed Work ### Self-hosted infrastructure / homelab (2022 – present) Multi-year public project documenting and operating a production-grade self-hosted stack. Website [homeserver.in.ua](https://homeserver.in.ua/), YouTube [@homeserver](https://www.youtube.com/@homeserver), GitHub [ravado](https://github.com/ravado). - **Virtualization:** Proxmox VE, QEMU/KVM, VFIO PCIe / GPU passthrough. - **Containerization:** Docker + Docker Compose, Portainer, ~15+ self-hosted services (self-hosted Git via Forgejo + Forgejo Actions for CI/CD, observability stack, photo/media, password management, dashboards). - **Observability:** Grafana + Loki + Alloy agents for log aggregation across nodes. - **Storage & networking:** NFS, Samba, **Tailscale mesh VPN** for offsite backup, self-signed internal certificate authority for TLS. - **Hardware tinkering:** Raspberry Pi projects (digital photo frame with sensor telemetry), repurposing old laptops with Linux. - **Automation:** Bash and Python scripting across nodes (backups, provisioning, maintenance). - Public knowledge-sharing in Ukrainian: written tutorials + video walkthroughs for the local self-hosting community. ### Wireless security — ongoing self-study Personal learning track focused on WPA/WPA2/WPS protocol internals: deauthentication mechanics, WPA 4-way handshake capture, GPU-accelerated dictionary/brute-force, WPS Pixie Dust. Strictly authorized targets (own lab equipment). Foundational, not a professional capability — included here to signal interest in wireless / RF security, not operator-level skill. ### stoik-visnyk Ukrainian-language Stoicism Telegram bot shipped to end users — small product, fully owned. --- ## Skills **Mobile:** iOS, Android, Xamarin.Native (iOS + Android), Xamarin.Forms, .NET MAUI, .NET for iOS, .NET for Android, custom native SDK bindings, MVVM, reactive patterns, offline-first / sync, push notifications, biometrics, 2FA, custom UI controls and renderers. **.NET / general:** C#, .NET 8 & .NET Framework, ASP.NET, WPF, XAML, SQLite, T-SQL, REST. **AI-assisted development:** Claude + Codex agent pipelines, sub-agent / skill design, agentic-coding team workflow, MCP-era tooling. **CI/CD & automation:** Azure Pipelines, TeamCity, Jenkins, AppCenter, Forgejo Actions, Cake, Bash, Python, NUnit. **Infrastructure:** Proxmox VE, QEMU/KVM, Docker / Docker Compose, Portainer, Grafana + Loki + Alloy, Tailscale, NFS/Samba, Linux administration (Debian family), self-signed TLS / CA management. **Practices:** SOLID, GoF patterns, Scrum / Kanban, code review, mentoring, full-cycle ownership. --- ## Education **Master's degree, Computer Science** Kremenchuk University of Economics, Information Technology and Management · 2008 – 2013 --- ## Languages - **Ukrainian** — native - **English** — full professional working proficiency