Sr Android Engineer - VPN/Networking

About Fusemachines

Founded in 2013, Fusemachines is a global provider of enterprise AI products and services, on a mission to democratize AI. Leveraging proprietary AI Studio and AI Engines, the company helps drive clients AI Enterprise Transformation, regardless of where they are in their Digital AI journeys. With offices in North America, Asia, and Latin America, Fusemachines provides a suite of enterprise AI offerings and speciality services that allow organizations of any size to implement and scale AI. Fusemachines serves companies in industries such as retail, manufacturing, and government.

Fusemachines continues to actively pursue the mission of democratizing AI for the masses by providing high-quality AI education in underserved communities and helping organizations achieve their full potential with AI.

Type: Full-Time, Remote (6-month contractual job with possibility of extension)

Required Skills:

Android

• Kotlin, coroutines/Flow, modern Android architecture
• VpnService: building and managing a VPN tunnel, routing, DNS handling, per-app VPN, always-on VPN behaviour.
• TUN interface concepts: packet capture/forwarding, MTU, TCP/UDP basics as they apply to tunnelling.
• Strong networking fundamentals: TCP/UDP, TLS, DNS, HTTP(S), proxies, NAT concepts, latency/packet loss handling.
• NDK/JNI experience (C/C++) for integrating VPN cores (strongly preferred)
• Release hardening: R8/Proguard, crash/ANR monitoring, Play Console workflows
• Building and shipping native libraries for multiple ABIs (arm64-v8a, armeabi-v7a).
• Experience with Gradle/CMake native builds.

Protocols

• WireGuard (keypairs, allowed-ips, handshake/keepalive behaviour)
• OpenVPN (TLS, config formats, cypher suites, connection stability)
• IKEv2/IPsec (EAP/TLS or PSK auth options, MOBIKE, NAT-T), strongSwan
• Shadowsocks / custom tunnelling (optional)

Security privacy

• Android Keystore, secure storage, encryption, certificate handling/pinning where appropriate
• Threat modelling, least-privilege design, privacy-first telemetry

Others

• Prior VPN product experience (consumer or enterprise)
• Play policy experience for VPN apps
• Experience building core VPN SDK + app shell architecture
• Backend/DevOps (Optional)
• One backend stack: Go/Java/Node/Python + PostgreSQL (or equivalent)
• Secure API design, secrets management (KMS/Vault), rate limiting
• Linux networking: iptables/nftables, routing, sysctl tuning
• Infra-as-code and CI/CD; monitoring (Prometheus/Grafana), centralized logs

Deliverables/success metrics

• Stable connections across protocols, minimal battery impact
• No DNS/IP leaks in standard test suites
• (Nice to have) Automated provisioning pipeline for servers and user/device configs (Nice to have) Monitoring dashboards + alerting; documented runbooks

Fusemachines is an Equal Opportunities Employer, committed to diversity and inclusion. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or any other characteristic protected by applicable federal, state, or local laws