Required Skills 5+ years of embedded C development on Linux-based platforms Strong proficiency in C programming pointers, memory management, IPC, event-driven architectures Experience with OpenWrt build system, package management, UCI configuration, and JFFS2/SquashFS overlay filesystems Familiarity with OpenSync or similar cloud-managed CPE frameworks (OVSDB, protobuf, MQTT telemetry) Experience with cellular modem integration AT commands, QMI, network interface management (rmnet/wwan) Strong understanding of Linux networking routing tables, metrics, netfilter, bridge interfaces, IPv4 and IPv6 dual-stack, neighbor discovery, DHCPv4/DHCPv6, SLAAC, and prefix delegation Understanding of TLS handshake with mutual authentication using X.509 certificates, certificate chain validation, and secure provisioning Knowledge of security and tunneling protocols GRE tunneling, IPsec, VPN overlays, and secure encapsulation for cloud-managed traffic Experience with event loop frameworks (libev, libuv, or similar) Proficiency with debugging tools GDB, strace, tcpdump, kernel logs, serial console Familiarity with Git, GitLab CI/CD, cross-compilation toolchains Understanding of WiFi standards (802.11ax/be) and wireless driver configuration Preferred Skills Experience with Qualcomm IPQ series SoCs (IPQ5018, IPQ9574) and NSS/PPE data path Experience with Broadcom BCM series chipsets (BCM4908, BCM6750, BCM63178) and Memory Direct Engine (MDE) / hardware acceleration Knowledge of Atheros/QCA/BCM wireless chipsets and CFG80211/mac80211 driver architecture Knowledge of DOCSIS cable modem interaction and WAN interface management Experience with PCIe and USB subsystems in embedded Linux (device enumeration, power management, error recovery) Familiarity with eSIM/eUICC provisioning (LPA, GSMA SGP.22) Experience with carrier aggregation, NR5G NSA/SA, and multi-band cellular configurations Understanding of

TR-069/TR-369

(USP) device management protocols Basic understanding of TR-181 data model for CPE device management and service configuration Experience with Kconfig-based build configuration Knowledge of flash storage considerations wear leveling, persistent partitions, factory reset flows Familiarity with thermal management and power management (battery-powered CPE)

Tools & Technologies Languages:

C, Shell scripting (sh/bash), Python (test automation)

OS/Platform:

OpenWrt (Linux 5.x/6.x kernel), ARM Cortex-A53/A73

Frameworks:

OpenSync, OVSDB, libev, protobuf-c, jansson (JSON)

Chipsets:

Qualcomm IPQ, Broadcom BCM, Atheros/QCA Networking:

iproute2, iptables/nftables, ovsdb-server, hostapd/wpa_supplicant,

GRE, IPsec Security:

OpenSSL/mbed

TLS, X.509

certificates, mTLS, certificate management

Cellular:

Qualcomm QCM/SDX modems, MHI, qcserial, AT+QENG/AT+

COPS Protocols:

IPv4, IPv6, DHCPv4/v6, DNS, MQTT, GRE, TLS 1.2/1.3

Build:

Make, Kconfig, OpenWrt feeds, cross-compilation (musl/glibc)

Debug:

GDB, valgrind, serial console, logpull analysis

VCS/CI:

Git, GitLab, merge request workflows Nice to Have Experience working directly with

ISP/MSO/OEM

partners Exposure to hardware bring-up and board support package (BSP) development Experience with Agile/Scrum in a firmware development context Familiarity with

SCTE/DOCSIS

standards Understanding of TR-181 data model parameters for WAN management, WiFi configuration, and device monitoring Experience with GRE tunnel implementation for backhaul traffic in managed WiFi deployments What You'll Work On Cellular failover/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 healthcheck frameworks Cloud-managed device configuration and telemetry reporting via MQTT Secure cloud connectivity using mTLS with X.509 certificate-based mutual authentication GRE tunnel management for cloud-redirected traffic Factory reset, firmware upgrade, and persistent storage management IPv4/IPv6 dual-stack network configuration, routing, and failover across DOCSIS and LTE interfaces WiFi radio configuration and performance optimization across Qualcomm / Broadcom platforms Kernel crash analysis and driver-level bug resolution

Top Skills:

1. Embedded C Development on Linux/OpenWrt o C programming, Linux internals, debugging, IPC, event-driven design 2. OpenSync/OpenWrt Platform Development o OpenSync Managers, OVSDB, UCI, MQTT, OpenWrt build system 3. Linux Networking & LTE/5G Cellular Integration o Routing, IPv4/IPv6, failover, QMI/MBIM, modem management, GRE/IPsec