Embedded C Developer

We are seeking an Embedded C Developer to work on next-generation residential gateway platforms that combine DOCSIS/Fiber WAN connectivity with LTE/5G cellular backup. The role involves developing and maintaining firmware on OpenWrt-based hardware running the OpenSync framework, supporting millions of deployed customer premises equipment (CPE) devices. Responsibilities

• Design, develop, and debug embedded C software for Linux-based residential gateway platforms (ARM/MIPS SoCs).
• Develop and maintain OpenSync managers that interact with OVSDB for cloud-managed configuration and state reporting.
• Implement and optimize LTE/5G cellular failover and fallback logic, including modem management, route arbitration, and WAN health checks.
• Develop LED state machine logic for multi-WAN connectivity scenarios.
• Interface with cellular modems using AT commands, QMI/MBIM, USB, and PCIe (MHI) protocols.
• Work with WiFi drivers (Qualcomm/Broadcom/Atheros) for 2.4GHz, 5GHz, and 6GHz radio configuration.
• Debug kernel-level issues including PCIe enumeration, USB device management, network driver crashes, and kernel panics.
• Implement and maintain secure communication channels using TLS with mutual authentication and tunneling protocols.
• Analyze and resolve field issues using device logs, crash dumps, and remote diagnostics.
• Develop init scripts, UCI configuration handlers, and persistent storage management for OpenWrt.
• Write unit tests and participate in code reviews through GitLab merge requests.
• Collaborate with hardware teams, QA, cloud platform engineers, and service provider partners., * Embedded C Development on Linux/OpenWrt.
• OpenSync/OpenWrt Platform Development.
• Linux Networking & LTE/5G Cellular Integration.

Additional Details

• Team Size: 8.
• Direct Reports: None.
• Strong hands-on experience developing OpenSync-based OpenWrt gateway firmware with LTE/5G cellular failover, combining deep Embedded C expertise, Linux networking, and cloud-managed CPE platforms.

Tools & Technologies

• C.
• Shell Scripting (sh/bash).
• Python.
• OpenWrt.
• Linux Kernel 5.x/6.x.
• ARM Cortex-A53/A73.
• OpenSync.
• OVSDB.
• libev.
• protobuf-c.
• jansson.
• Qualcomm IPQ.
• Broadcom BCM.
• Atheros/QCA.
• iproute2.
• iptables.
• nftables.
• hostapd.
• wpa_supplicant.
• GRE.
• IPsec.
• OpenSSL.
• mbedTLS.
• X.509 Certificates.
• TLS 1.2 / TLS 1.3.
• MQTT.
• QMI.
• MHI.
• Make.
• Kconfig.
• GDB.
• Valgrind.
• Git.
• GitLab.

What You’ll Work On

• Cellular failover and fallback state machines with sub-second transition handling.
• LED indication logic for multi-WAN connectivity states.
• Modem health monitoring and subsystem restart/recovery.
• Internet reachability health-check frameworks.
• Cloud-managed device configuration and telemetry reporting via MQTT.
• Secure cloud connectivity using mTLS and X.509 certificate-based mutual authentication.
• GRE tunnel management for cloud-redirected traffic.
• Factory reset, firmware upgrades, and persistent storage management.
• IPv4/IPv6 network configuration, routing, and failover across DOCSIS and LTE interfaces.
• WiFi radio configuration and performance optimization across Qualcomm and Broadcom platforms.
• Kernel crash analysis and driver-level bug resolution.

Years of Experience

• 14 Years of Experience.

TekWissen Group is an equal opportunity employer supporting workforce diversity.

• 5+ years of embedded C development on Linux-based platforms.
• Strong proficiency in C programming, memory management, IPC, and event-driven architectures.
• Experience with OpenWrt build systems, package management, UCI configuration, and JFFS2/SquashFS overlay file systems.
• Familiarity with OpenSync, OVSDB, Protobuf, and MQTT telemetry.
• Experience with cellular modem integration using AT commands, QMI, and WWAN interfaces.
• Strong understanding of Linux networking, routing tables, IPv4/IPv6 dual-stack networking, DHCPv4, DHCPv6, SLAAC, and prefix delegation.
• Understanding of TLS mutual authentication using X.509 certificates.
• Knowledge of GRE tunneling, IPsec, VPN overlays, and secure encapsulation technologies.
• Experience with event loop frameworks such as libev or libuv.
• Proficiency with debugging tools including GDB, strace, tcpdump, kernel logs, and serial consoles.
• Familiarity with Git, GitLab CI/CD, and cross-compilation toolchains.
• Understanding of WiFi standards including 802.11ax and 802.11be.

Preferred Skills

• Experience with Qualcomm IPQ series SoCs including IPQ5018 and IPQ9574.
• Experience with Broadcom BCM series chipsets including BCM4908, BCM6750, and BCM63178.
• Knowledge of Atheros, Qualcomm, and Broadcom wireless driver architectures.
• Experience with DOCSIS cable modem environments.
• Experience with PCIe and USB subsystems in embedded Linux.
• Familiarity with eSIM and eUICC provisioning technologies.
• Experience with NR5G NSA/SA and carrier aggregation.
• Understanding of TR-069 and TR-369 (USP) device management protocols.
• Familiarity with TR-181 data models.
• Experience with Kconfig-based build environments.
• Knowledge of flash storage management, wear leveling, and factory reset processes.
• Familiarity with thermal and power management for embedded platforms.

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