Sr Principal Software Engineer -Core Systems & Libraries (Onsite)

Date Posted: 2026-07-02 Country: United States of America Location: US-AL-HUNTSVILLE-382 ~ 420 Jan Davis Dr ~ DAVIS 382 Position Role Type: Onsite U.S. Citizen, U.S. Person, or Immigration Status Requirements: U.S. citizenship is required, as only U.S. citizens are authorized to access information under this program/contract. Security Clearance Type: None/Not Required Security Clearance Status: Not Required Design the Foundation of Next-Generation Avionics Join the growing Collins Aerospace Core Systems and Libraries team and play a key role in shaping the software foundation that powers modern aircraft. We are seeking a Senior Principal Software Engineer who thrives on solving complex technical challenges and driving high-impact solutions across safety-critical systems. In this role, you will lead the architecture and development of core software components, libraries, and tools that enable scalable, certifiable avionics platforms. You’ll work across the full software lifecycle, partnering with cross-functional teams to deliver high-quality solutions aligned with civil and military certification standards. This is a unique opportunity to influence system-level design, advance open architecture initiatives, and contribute to technologies that define the future of aerospace. Location: Onsite in Huntsville, AL What You Will Do Lead the architecture and design of core software components, libraries, and tooling aligned to avionics system requirements Drive technical direction and execution across development and verification activities for safety-critical software (DO-178) Define and manage software requirements, decomposition, and traceability across complex systems Develop and verify software using modern C++ and object-oriented design principles Own and produce DO-178 certification artifacts, including DAL-A deliverables Lead and support certification efforts, including engagement with customers and regulatory authorities Conduct and contribute to peer reviews to ensure quality, consistency, and compliance across the lifecycle Collaborate cross-functionally with engineering, program leadership, and customers to align technical solutions with program objectives Willing and Able to travel as required (domestic and international <10%). What You Will Learn Gain hands-on experience with cutting-edge and emerging technologies that are shaping the future of avionics and aerospace systems Build end-to-end expertise across the full product lifecycle, from requirements and design through verification and delivery of safety-critical systems Develop a deep understanding of software certification (DO-178) and how world-class avionics products meet rigorous regulatory standards Learn how to design, scale, and sustain software product lines that support a wide range of platforms and global customers Qualifications You Must Have Typically requires a degree in Science, Technology, Engineering or Mathematics (STEM) and minimum 10 years prior relevant experience or an Advanced Degree in a related field and minimum 7 years of experience U.S. citizenship is required, as only U.S. citizens are authorized to access information under this program/contract. Proven experience designing and developing software architecture, libraries, or platform-level components within an aerospace or safety-critical environment Demonstrated ability to lead technical execution of projects, including customer engagement and presenting to senior stakeholders Hands-on experience supporting DO-178 software development and certification activities (e.g., requirements, verification, or certification artifacts) Experience working across cross-functional engineering and program teams to deliver complex, integrated solutions Qualifications We Prefer Experience with C++ and VxWorks. Experience writing High-Level and Low-Level Requirements. Experience writing Test Cases and Automated Test Procedures. Experience with Civil Certification DO-178 – DAL A preferred. Experience with design and development of Flight Management Systems, Software, Aircraft Applications or Middleware. Familiar with revision control concepts and tools (e.g. GIT, Subversion, JIRA). What We Offer Medical, dental, and vision insurance Three weeks of vacation for newly hired employees Generous 401(k) plan that includes employer matching funds and separate employer retirement contribution, including a Lifetime Income Strategy option Tuition reimbursement program Student Loan Repayment Program Life insurance and disability coverage Optional coverages you can buy pet insurance, home and auto insurance, additional life and accident insurance, critical illness insurance, group legal, ID theft protection Birth, adoption, parental leave benefits Ovia Health, fertility, and family planning Adoption Assistance Autism Benefit Employee Assistance Plan, including up to 10 free counseling sessions Healthy You Incentives, wellness rewards program Doctor on Demand, virtual doctor visits Bright Horizons, child and elder care services Teladoc Medical Experts, second opinion program And more! Learn More & Apply Now! Avionics delivers advanced cockpit displays, vision systems, and comprehensive digital solutions for global government, commercial and business aviation customers. We provide connectivity and managed data services to ensure safety and seamless communication for passengers, crews, and militaries, from aircraft and airports to air traffic management. Join us in creating solutions that connect the world, one flight at a time. Start your application today. *Please ensure the role type (defined below) is appropriate for your needs before applying to this role. Onsite: Employees who are working in Onsite roles will work primarily onsite. This includes all production and maintenance employees, as they are essential to the development of our products. At Collins, the paths we pave together lead to limitless possibility. And the bonds we form – with our customers and with each other -- propel us all higher, again and again. Apply now and be part of the team that’s redefining aerospace, every day. 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 RTX is an aerospace and defense company that provides advanced systems and services for commercial, military and government customers worldwide. It comprises three industry-leading businesses – Collins Aerospace, Pratt & Whitney, and Raytheon. Its 195,000 employees enable the company to operate at the edge of known science as they imagine and deliver solutions that push the boundaries in quantum physics, electric propulsion, directed energy, hypersonics, avionics and cybersecurity. The company, formed in 2020 through the combination of Raytheon Company and the United Technologies Corporation aerospace businesses, is headquartered in Arlington, Virginia.