Embedded C Developer – OpenSync/ WiFi Gateway-OnSite, Englewood, Colorado, United States

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

About the Role

We're looking for an Embedded C Developer to work on next-generation residential gateway platforms that combine DOCSIS/fiber WAN connectivity with LTE/5G cellular backup. You'll be developing and maintaining firmware on OpenWrt-based hardware running the OpenSync framework, with direct impact on millions of deployed customer premises equipment (CPE).

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, route arbitration, and WAN healthchecks

• Develop LED state machine logic to provide accurate device status indication across complex multi-WAN scenarios

• Interface with cellular modems via 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 via GitLab merge requests

• Collaborate with hardware teams, QA, cloud platform engineers, and service provider partners

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/mbedTLS, 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

About Cognizant’s IoT Practice:

Intelligent, IoT-enabled products will soon result in the proliferation of data and disrupt virtually all industries. To be successful, both large and small companies must leverage IoT capabilities by designing modern products that fundamentally connect people with processes. Within Cognizant IOT, we engineer industry-aligned, IoT-enabled products that merge industry needs with human drivers. Our intelligent products will revolutionize experiences and result in exciting, transformative outcomes. Without human-centered thinking, connected products are just standalone things—but with it, our modern connected products facilitate a unified way of life enjoyed by all.

*Please note, this role is not able to offer visa transfer or sponsorship now or in the future*

Applications will be accepted until Aug31 , 2026
LI#- #LI-SC6

Compensation & Benefits

$104,000– $118,000 per year + Cost of Living Allowance

Bonus + Comprehensive Benefits

Additional Information

Onsite role
⚠️ Visa sponsorship is not available now or in the future. Candidates requiring sponsorship will not be considered.

Benefits: Cognizant offers the following benefits for this position, subject to applicable eligibility requirements:

• Medical/Dental/Vision/Life Insurance

• Paid holidays plus Paid Time Off

• 401(k) plan and contributions

• Long-term/Short-term Disability

• Paid Parental Leave

• Employee Stock Purchase Plan

Sobre a Cognizant
Cognizant (NASDAQ: CTSH) é uma construtora de IA e fornecedora de serviços de tecnologia, criando a ponte entre o investimento em IA e o valor para as empresas por meio do desenvolvimento de soluções de IA completas para nossos clientes. Nossa profunda experiência em setores, processos e engenharia nos permite incorporar o contexto único de cada organização em sistemas tecnológicos que potencializam a capacidade humana, geram resultados tangíveis e mantêm empresas globais à frente em um mundo em rápida transformação. Saiba mais em cognizant.ai ou @cognizant.

A Cognizant é uma empregadora que investe em equidade. Sua candidatura não será pautada em raça, cor, gênero, sexualidade, credo, origem, deficiência, gravidez ou qualquer outra característica protegida pelas leis brasileiras.

Informações adicionais de emprego
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Embora nosso sistema permita a candidatura em todos os idiomas, o(s) idioma(s) e o(s) nível(is) de proficiência exigidos para o trabalho variam. No entanto, é necessário um nível básico de inglês para fins de comunicação em toda a empresa.

Se você tem uma deficiência que requer adaptações razoáveis para procurar uma vaga de emprego ou enviar uma candidatura, envie um e-mail para [email protected] com sua solicitação e informações de contato.