Embedded C Developer – OpenSync/OpenWrt WiFi Router with Cellular role

Title: Embedded C Developer – OpenSync/OpenWrt WiFi Router with Cellular

Location: Denver, CO – 4 Days Onsite/Week

Experience: 5+ Years
 

Job Description

We are looking for an experienced Embedded C Developer with strong expertise in Linux, OpenWrt, OpenSync, WiFi networking, and cellular modem integration. The ideal candidate will have hands-on experience developing embedded software for WiFi routers, gateways, and cloud-managed CPE platforms.

Required Skills

• 5+ years of hands-on Embedded C development on Linux-based platforms.
• Strong proficiency in C programming, including pointers, memory management, IPC, and event-driven architectures.
• Experience with the OpenWrt build system, package management, UCI configuration, JFFS2, and SquashFS overlay filesystems.
• Experience with OpenSync or similar cloud-managed CPE frameworks.
• Strong knowledge of OVSDB, protobuf, and MQTT telemetry.
• Experience with cellular modem integration, including AT commands, QMI/MBIM, and network interfaces such as rmnet/wwan.
• Strong understanding of Linux networking, including:
  • Routing tables and metrics
  • Netfilter
  • Bridge interfaces
  • IPv4/IPv6 dual-stack
  • Neighbor Discovery
  • DHCPv4/DHCPv6
  • SLAAC
  • Prefix Delegation
• Understanding of TLS handshake and mutual authentication, X.509 certificates, certificate chain validation, and secure provisioning.
• Knowledge of GRE tunneling, IPsec, VPN overlays, and secure encapsulation for cloud-managed traffic.
• Experience with event-loop frameworks such as libev, libuv, or similar.
• Proficiency with debugging tools including GDB, strace, tcpdump, kernel logs, and serial console.
• Familiarity with Git, GitLab CI/CD, and cross-compilation toolchains.
• Understanding of WiFi standards 802.11ax/802.11be and wireless driver configuration.

Top Skills

1. Embedded C Development – Linux/OpenWrt

• C programming
• Linux internals
• Debugging
• IPC
• Event-driven architecture

2. OpenSync/OpenWrt Platform Development

• OpenSync Managers
• OVSDB
• UCI
• MQTT
• OpenWrt build system

3. Linux Networking & LTE/5G Cellular Integration

• Routing
• IPv4/IPv6
• Network failover
• QMI/MBIM
• Cellular modem management
• GRE/IPsec