Ericsson Enterprise Wireless Solutions is expanding its modem engineering team in North America, focused on end-to-end development of advanced 5G cellular use cases in collaboration with global Ericsson teams and leading chipset partners. This core team is driving the development of next-generation enterprise and industrial 5G solutions on advanced cellular chipset platforms. We are looking for an experienced Principal Modem Engineer to lead the architecture, development, and integration of cellular modem drivers and eSIM/eUICC provisioning stacks on OpenWrt-based platforms. In this role, you will own the full modem connectivity stack - from kernel-level USB/PCIe drivers through QMI/RMNET interfaces to eSIM profile lifecycle management. You will drive technical strategy, support the growth of engineering teams, and establish best practices for carrier-grade modem and eSIM deployments across 5G product lines. This is a full-time position based in the USA. What you will do: As a Modem Firmware Principal Engineer - Modem, you will design, develop, and optimize modem host platform software for LGA modules. This role offers a unique opportunity to influence platform architecture early, take strong technical ownership, and deliver high-performance, power-efficient 5G modem solutions at global scale. - Architect and own the end-to-end modem and eSIM integration stack on OpenWrt platforms - Design and develop Linux kernel drivers for modem interfaces (USB/PCIe/SDIO) - Implement and optimize QMI/RMNET/AT command layers for modem control and data path - Architect and implement a Local Profile Assistant (LPA) for eSIM profile lifecycle management - Develop secure channel protocols (SCP03, SCP80/81) between the platform and eUICC - Integrate SM-DP+ provisioning flows for remote profile download and activation - Implement connection management with failover, reconnection, and multi-SIM orchestration - Drive modem firmware update (FOTA) strategy and implementation - Lead carrier certification efforts (GCF, PTCRB) and GSMA compliance (SAS-UP, SAS-SM) - Define the technical roadmap for next-generation modem and eSIM platform capabilities - Design and implement CI/CD pipelines and automated test frameworks for modem and eSIM firmware - Build hardware-in-the-loop (HIL) test infrastructure and automated fleet provisioning workflows - Establish coding standards, review processes, and architectural guidelines for the team - Support and develop senior and mid-level engineers on modem driver and eSIM development - Collaborate with mobile network operators, eUICC vendors, and chipset vendors for interoperability The skills you bring - 10+ years in embedded Linux, modem, or telecom development; 5+ years in cellular modem driver development - 3+ years each with eSIM/eUICC integration (GSMA RSP), OpenWrt or similar embedded Linux, and technical leadership - Linux kernel modem driver development (USB, PCIe, qmi_wwan, mhi) - OpenWrt/LEDE build system, package development, and platform customization - eSIM/eUICC architecture and GSMA RSP specifications (SGP.02, SGP.22, SGP.32) - Cellular modem control interfaces (QMI, RMNET, AT commands, NCM) - Secure element communication (ISO 7816, APDU, SCP03) - Proficiency in C/C++ for embedded Linux and real-time systems - Network stack expertise (iptables/nftables, iproute2, netifd, routing, NAT) - PKI infrastructure, certificate management, and secure provisioning - Bachelor's degree in Electrical Engineering, Computer Engineering, Computer Science, or Telecommunications (Master's or Ph.D. preferred) - Experience with Qualcomm SDX-series modem platforms, eUICC vendors, and CI/CD tooling (Jenkins, GitLab CI, GitHub Actions) is a plus DISCLAIMER: The above statements are intended to describe the general nature and level of work being performed by employees in this position. They are not an exhaustive list of all responsibilities, duties and skills required for this position, and you may be required to perform additional job tasks as assigned. Primary country and city: United States (US) || Santa Clara (Country/ City) Job details: Developer Compensation and Benefits at Ericsson At Ericsson, we know that our people are the key to our success. We offer a competitive package to help with your individual needs and goals. Seattle, NY, NJ, Santa Clara Your Pay The salary range for this position is dependent on various factors including, but not limited to, location, and the candidate's combination of job-related knowledge, qualifications, skills, education, training, and experience. The salary range for this position is Santa Clara, CA : $232,000-292,500 Short-Term Variable Compensation Plan : Your pay also includes the opportunity for an annual bonus. Actual bonus payouts are based on performance of the business against the unit's objectives, individual performance, and the individual bonus target. Certain eligibility and pro-ration rules apply. Your Health Ericsson Enterprise Wireless Solutions offers excellent, competitive employee benefits, such as: subsidized, nationwide PPO medical benefit options including a low-deductible Point of Service Plan and a qualifying High Deductible Health Plan (HDHP), with a generous company-provided HSA contribution. For California employees, we offer a subsidized HMO option through Kaiser. Ericsson Enterprise Wireless Solutions also offers subsidized dental and vision coverage. Your Financial Security We invest in both your short and long-term financial wellbeing. Our 401(k) plan has a 4% company match and immediate vesting. Employees will also receive company-paid employee basic life and AD&D insurance and company-paid disability benefits. Your Time Your work-life balance is important to us. New employees are provided a minimum of 15 days of accrued vacation, up to 3 personal days per year, 11 annual holidays, 8 hours of volunteer time, and 80 hours of sick time annually. Please note paid time off is pro-rated based on the employee's start date. Furthermore, Ericsson provides up to 16 weeks of paid maternity leave and 6 weeks of parental or adoption leave at 100% of pay. Additional Benefits Ericsson Enterprise Wireless Solutions offers other company-paid benefits such as a comprehensive Employee Assistance Program, mobile therapy, and volunteer paid time off.