Embedded C Engineer: OpenWrt WiFi Gateway with LTE Backup

Cognizant; Englewood (CO); On-site; USD 104,000 - 118,000; Full time

Benefits offered by this job

Medical/Dental/Vision/Life Insurance

401(k) plan

Paid holidays

Paid Time Off

Disability Insurance

Parental Leave

Employee Stock Purchase Plan

Job summary

Cognizant is seeking an Embedded C Developer to work on OpenWrt/OpenSync-based residential gateways, delivering LTE/5G cellular backup and multi‑WAN reliability. You will develop firmware for Linux-based platforms (ARM/MIPS) and collaborate with hardware, QA, and cloud teams to implement secure, observable cloud-managed devices.

With a focus on kernel debugging, device management via OVSDB, and OpenWrt tooling, this onsite role in Englewood, CO requires strong embedded Linux and modem

Qualifications

• 5+ years of embedded C development on Linux-based platforms.
• Experience with OpenWrt build system, package management, and UCI configuration.
• Familiarity with OpenSync or similar cloud-managed CPE frameworks (OVSDB, protobuf, MQTT).
• Experience with cellular modem integration and network interface management.
• Strong understanding of Linux networking, routing, IPv4/IPv6, and TLS with mutual authentication.

Responsibilities

• Design, develop, and debug embedded C software for Linux-based residential gateway platforms (ARM/MIPS SoC).
• Develop and maintain OpenSync managers—event-driven daemons that interact with OVSDB for cloud-managed configuration and state reporting.
• Implement and optimize LTE/5G cellular failover and fallback logic including modem management and WAN healthchecks.
• Develop LED state machine logic for multi-WAN scenarios.
• Interface with cellular modems via AT commands, QMI/MBIM, USB, and PCIe (MHI) protocols.
• Work with WiFi drivers for 2.4/5/6 GHz configurations and secure provisioning.
• Debug kernel-level issues including PCIe enumeration and network driver crashes.
• Implement secure communication channels using TLS with mutual authentication.
• Analyze field issues using 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 via GitLab MRs.
• Collaborate with hardware teams, QA, cloud engineers, and service provider partners.

Skills

Embedded C

Linux networking

TLS/mTLS

GitLab CI/CD

Kernel debugging

C programming

OpenWrt

OVSDB

Tools

OpenWrt

OVSDB

protobuf-c

GDB

libev

protobuf

j ull nson

Job description

Cognizant is seeking an Embedded C Developer to work on OpenWrt/OpenSync-based residential gateways, delivering LTE/5G cellular backup and multi‑WAN reliability. You will develop firmware for Linux-based platforms (ARM/MIPS) and collaborate with hardware, QA, and cloud teams to implement secure, observable cloud-managed devices.

With a focus on kernel debugging, device management via OVSDB, and OpenWrt tooling, this onsite role in Englewood, CO requires strong embedded Linux and modem