Contact person: Business Client

Phone:Show

Email:Show

Location: Engen, Germany

Budget: Recommended by industry experts

Time to start: As soon as possible

Project description:
"Extension: Looking for a Senior Developer to Implement Deep System Features (Android, iOS, Linux)
The core architecture, the unified cross-platform UI concept, and the overall structure (WebView-based UI, central rule engine, proxy core, marketplace, desktop integration) have already been prepared. Our lead developer is currently focusing on the macOS and Windows implementations.
We now need an additional senior engineer who will work closely with our lead developer and implement the low-level system components for the remaining platforms:
Android: VpnService/TUN integration, tun2proxy pipeline, system networking APIs, DNS handling, per-app routing, performance optimization
iOS: Network Extension (NEPacketTunnel and NEAppProxy), Per-App VPN, DNS proxying, Keychain and MDM integration
Linux: iptables, nftables, TPROXY, eBPF or TC integration, per-user routing, Netlink communication, systemd services, packaging
This requires a developer with real platform expertise so that the implementations reach a stable and professional level comparable to Proxifier.
Why one senior developer (or a very small specialist team) is ideal for all three platforms:
Ensures equal technical depth and consistent quality across Android, iOS, and Linux.
Provides unified technical decision-making across all layers such as DNS handling, interception logic, logging, and proxy routing.
Enables seamless collaboration with our lead developer who is responsible for Windows and macOS.
Reduces coordination overhead because communication remains within one technical line instead of multiple freelancers.
Guarantees a consistent WebView-to-native interface on every platform, so UI actions and system operations behave the same everywhere.
Improves long-term maintainability because the core platform architecture is designed by one expert who can later onboard additional developers.
Required experience for the ideal candidate:
Experience across Android (VpnService/TUN, tun2socks-style engines), iOS (Network Extension, Per-App VPN), and Linux (netfilter, nftables, TPROXY, eBPF).
Strong knowledge of user-mode proxying and protocols such as HTTP, HTTPS CONNECT, SOCKS4/5, UDP handling, DNS-over-HTTPS and DNS-over-TLS.
Ability to build robust WebView bridge layers for Android, iOS, and desktop environments.
Background in enterprise environments including MDM, Intune, managed configurations, and Linux package management (DEB/RPM)." (client-provided description)