Senior Principal Software Engineer

Date Posted: 2026-09-10 Country: United States of America Location: US-MA-MARLBOROUGH-MA2 ~ 1001 Boston Post Rd ~ BLDG 2 Position Role Type: Onsite U.S. Citizen, U.S. Person, or Immigration Status Requirements: The ability to obtain and maintain a U.S. government issued security clearance is required.​ U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance Security Clearance Type: DoD Clearance: Secret Security Clearance Status: Active and existing security clearance required after day 1 At RTX, the world's largest aerospace and defense company, 185,000 great minds are united by purpose and inspired to make a difference solving the world’s most complex problems. With our three market leading businesses, world-class operations and investments in research and development, we offer capabilities and opportunity no one else can. Together, we push the boundaries of known science and find new ways to connect and protect our world. Raytheon brings the strength of more than 100 years of experience and renowned engineering expertise to meet the needs of today’s mission and stay ahead of tomorrow’s threat. We deliver solutions that help our nation and allies defend freedoms and deter aggression, creating a safer, more secure world. Join us and help shape the future of aerospace and defense. This is your opportunity to join the Receiver Exciter and Processing Architecture Department as a Senior Principle Software Engineer. The team’s primary goal is to design, architect, and implement signal processing algorithms on a variety of high-performance processing platforms – including CPUs, FPGAs and GPUs, on COTS and semi-custom hardware platforms, for next generation radar systems deployed on land and sea. This is your opportunity to join the Receiver, Exciter & Processing Architecture (REPA) Department as a Senior Principal Software Engineer. The team’s primary goal is to design, architect, and implement signal processing algorithms on a variety of high-performance processing platforms – including CPUs, FPGAs and GPUs, on COTS and semi-custom hardware platforms, for next generation radar systems deployed on land and sea. What You Will Do : Investigate and implement on-prem LLM and agentic harness in a sandboxed environment Investigate moving the following activities to an AI agentic workflow: Develop real-time C++ and/or Cuda implementations of signal processing algorithms or control functions for sensor systems running on a distributed Linux backend. Write unit tests and integration tests to satisfy requirements. Analyze numerical correctness and runtime latency. Maintain high code quality by supporting code reviews and continuous integration. This 1st shift role will be 100% onsite and based in Marlborough, MA. Qualifications You Must Have : Typically requires a degree in Science, Technology, Engineering or Mathematics (STEM) and a minimum of 10 years of prior relevant experience. C++ software development experience in Linux environments. Experience deploying on-prem LLM and agentic AI. The ability to obtain and maintain a U.S. government issued Secret security clearance is required. U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance. Qualifications We Value : Experience developing GPU software - particularly with Nvidia Cuda - is highly desirable. Real-time software development experience. Experience with developer tools (Git, Cmake, Googletest, gdb, profiler, Jenkins, Jira). Experience with scripting (Python, shell, bash). Experience with Agile methodologies (Scrum, Kanban). Radar or DSP knowledge. Active / Existing Secret. U.S. Security Clearance. What We Offer : Our values drive our actions, behaviors, and performance with a vision for a safer, more connected world. At RTX we value: Safety, Trust, Respect, Accountability, Collaboration, and Innovation. This position offers relocation based on candidate eligibility. Learn More & Apply Now! Please consider the following role type definition as you apply for this role. Onsite: Employees who are working in Onsite roles will work primarily onsite. Clearance Information: This position requires a security clearance. DCSA Consolidated Adjudication Services (DCSA CAS), an agency of the Department of Defense, handles and adjudicates the security clearance process. More information about Security Clearances can be found on the US Department of State government website here: https://www.state.gov/m/ds/clearances/c10978.htm As part of our commitment to maintaining a secure hiring process, candidates may be asked to attend select steps of the interview process in-person at one of our office locations, regardless of whether the role is designated as on-site, hybrid or remote. The salary range for this role is 132,400 USD - 251,600 USD. The salary range provided is a good faith estimate representative of all experience levels. RTX considers several factors when extending an offer, including but not limited to, the role, function and associated responsibilities, a candidate’s work experience, location, education/training, and key skills. Hired applicants may be eligible for benefits, including but not limited to, medical, dental, vision, life insurance, short-term disability, long-term disability, 401(k) match, flexible spending accounts, flexible work schedules, employee assistance program, Employee Scholar Program, parental leave, paid time off, and holidays. Specific benefits are dependent upon the specific business unit as well as whether or not the position is covered by a collective-bargaining agreement. Hired applicants may be eligible for annual short-term and/or long-term incentive compensation programs depending on the level of the position and whether or not it is covered by a collective-bargaining agreement. Payments under these annual programs are not guaranteed and are dependent upon a variety of factors including, but not limited to, individual performance, business unit performance, and/or the company’s performance. This role is a U.S.-based role. If the successful candidate resides in a U.S. territory, the appropriate pay structure and benefits will apply. RTX anticipates the application window closing approximately 40 days from the date the notice was posted. However, factors such as candidate flow and business necessity may require RTX to shorten or extend the application window. RTX is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability or veteran status, or any other applicable state or federal protected class. RTX provides affirmative action in employment for qualified Individuals with a Disability and Protected Veterans in compliance with Section 503 of the Rehabilitation Act and the Vietnam Era Veterans’ Readjustment Assistance Act. Privacy Policy and Terms: Click on this link to read the Policy and Terms