Andrii Pasichnyk
Software Engineer
Profile
I'm a software engineer at InTallyCon, where I work on our WireGuard VPN: the Flutter plugin and apps on top, Go and C++ underneath, on Android, iOS, macOS and Windows. I also write Go backends and work on Yocto-based embedded Linux. Outside work I dig into the Linux kernel (my WireGuard patch doubled throughput on a single-core router) and keep a couple of Android apps going.
Experience
Software Engineer
02/2026 - Present- The open-source Flutter plugin for WireGuard we started from was abandoned in 2024 and ran on each platform's stock backend. Those backends drop the tunnel whenever peers change, which ruled out direct P2P connections. I forked it and turned it into our own plugin for Android, iOS, macOS and Windows.
- Wrote one data plane on top of wireguard-go that owns the tunnel and the UDP socket itself, and reused it on every platform (gomobile, cgo). Peers now change without a reconnect, and a fix lands on all platforms at once.
- On top of it built a P2P core in Go, so devices can connect to each other directly instead of going through a relay.
- Added split DNS and LAN bypass. Before that, turning on a full tunnel cut users off from their own router and NAS.
- On Windows the old plugin needed admin rights to start the tunnel. I replaced that with a C++ SYSTEM service on WireGuard-NT: one install, after that the app talks to it over a named pipe, and the private key never leaves the service.
- Besides the VPN, I built several Flutter apps and Go backend services, take part in architecture decisions and review code on the Flutter and Go projects.
- Also work on embedded Linux built with Yocto (BitBake recipes, layers, cross-compilation, systemd).
Open Source: Linux Kernel / WireGuard
2026- Got WireGuard on a cheap single-core router chip (Realtek RTL8196E, 400 MHz) running twice as fast: TCP went from 9.4 to 18.8 Mbit/s, and ping through a busy tunnel dropped from 108 to 31 ms.
- The cipher wasn't the bottleneck. Profiling showed a context switch on almost every packet, because WireGuard hands packets to worker queues built for multi-core machines. My patch skips those queues when there is only one CPU.
- Found a memory leak in WireGuard that had been in the kernel since 2019, and sent the fix to the netdev mailing list.
Flutter Developer
2023 - 2024- Wrote SovaWallet, a Flutter crypto wallet for phones and desktop.
- The coin's reference code was in Pascal, so I ported its hashing, signatures and network protocol to Dart.
- Where Dart was too slow, called C++ libraries through FFI.
- The wallet picks a node on its own, switches when one goes down and syncs in the background.
Android Developer
2021 - Present- My Notes has 10k+ downloads. Its block-based editor is my own, written without third-party editor libraries.
- Encly is on Google Play and F-Droid: encrypted notes and tasks with no account, no cloud and no internet permission at all.
- Both are built with Clean Architecture, MVVM, Hilt and Room, with database migrations between versions.
- In other projects used the Google Maps API for tracking, geocoding and routes.
Web Developer
2015 - 2020- Built REST APIs, admin panels and small SaaS tools in PHP, JavaScript and SQL.
Technical Skills
Programming Languages
Go, Dart, C++, C, Kotlin, Swift, Java, SQL.
Networking & VPN
WireGuard (wireguard-go, WireGuard-NT, Linux kernel), TCP/IP, UDP, DNS, NAT, iptables, P2P, REST, WebSocket, gRPC, Protocol Buffers.
Mobile & Desktop
Flutter (platform plugins, Dart FFI, Bloc, Riverpod), Android (VpnService, Jetpack Compose, Room, Hilt, WorkManager), iOS/macOS (Network Extension, Keychain), Windows (Win32, services, named pipes, DPAPI, CNG).
Embedded Linux
Yocto Project, OpenEmbedded, BitBake, cross-compilation, systemd, Linux kernel patches, kernel profiling.
Backend & Data
Go services (REST, encryption at rest, SQLite without cgo), PostgreSQL, SQLite, Firebase.
Practices
Software architecture, Clean Architecture, MVVM, code review, Git, GitLab CI, GitHub Actions, unit testing.