Principal Software Engineer Onsite

Prattwhitney; Huntsville (AL); On-site; USD 108,000 - 205,000; Full time

Benefits offered by this job

Medical insurance

Dental insurance

Vision insurance

401(k) match

Life insurance

Short-term disability

Long-term disability

Paid time off

Job summary

RTX is seeking a Senior Software Engineer in Huntsville, AL to design, develop, test, and maintain high-performance C++ software across SDLC stages. The role emphasizes Unix/Linux environments, system-level programming, APIs, and hardware interfaces within an on-site DoD context.

Qualified candidates will have a STEM degree with 8+ years of experience, strong C++ skills, and the ability to obtain interim secret clearance; U.S. citizenship is required due to security requirements.

Qualifications

• Typically requires STEM degree and 8+ years of relevant experience.
• Experience in C++ software development.
• Experience with Unix/Linux environments.
• Experience with GDB and Valgrind tools.

Responsibilities

• Design, develop, test, and maintain high-performance C++ software.
• Work in Unix/Linux environments; shell scripting and system-level programming.
• Integrate with APIs, system libraries, and hardware interfaces.
• Participate in Agile/Scrum development cycles.
• Perform code reviews and ensure code quality.
• Stay current with industry trends including AI, DevSecOps and modern development practices.

Skills

C++ development

Unix/Linux debugging

Security clearance required

Interpersonal collaboration

Education

STEM degree

Tools

GDB

Valgrind

Job description

Date Posted: 2026-08-31 Country: United States of America Location: US-AL-HUNTSVILLE-401 ~ 401 Jan Davis Dr NW ~ JAN DAVIS 401 Position Role Type: Onsite U.S. Citizen, U.S. Person, or Immigration Status Requirements: Active and transferable U.S. government issued security clearance is required prior to start date. 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: Ability to obtain INTERIM U.S. government issued security clearance is required prior to start date 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.

As a Senior Software Engineer, you will support one or more phases of the System Development Life Cycle (SDLC) - requirements, design, development using C++, test, validation, and maintenance. This is an onsite role based in Huntsville, AL.

What You Will Do

• Design, develop, test, and maintain high‑performance software applications using C++
• Work within Unix/Linux operating systems, including shell scripting, debugging, and system-level programming
• Implement scalable and maintainable software solutions following best practices in architecture and design
• Collaborate with cross-functional teams, including product management, QA, and DevOps
• Conduct code reviews and provide feedback to ensure code quality and adherence to standards
• Troubleshoot and optimize existing software for performance, reliability, and scalability
• Integrate with APIs, system libraries, and hardware interfaces as needed
• Develop and maintain documentation, including technical specifications and user guides
• Participate in Agile/Scrum development cycles, contributing to sprint planning and estimation
• Stay current with industry trends and advancements in modern languages, Artificial Intelligence (AI), Development, Security, and Operations (DevSecOps), and other methodologies and technologies, especially in relation to complex systems.
• Travel may occasionally be required.

What You Will Learn

• Agile methodology and the associated tools.
• Modern Development, Security, and Operations (DevSecOps) and Continuous Integration/Continuous Delivery techniques.
• Test-Driven Multi-Disciplined Capability (TDMC) Product Development methodology.
• Work across engineering disciplines to develop solutions to complex problems in support of defense systems.
• Use AI to increase efficiency, resulting in higher quality products, across the SDLC.

Qualifications

• Typically requires a degree in Science, Technology, Engineering or Mathematics (STEM) and a minimum of 8 years of prior relevant experience unless prohibited by local laws/regulations.
• Experience in C++ software development
• Experience working and debugging in Unix/Linux environments
• Experience with tools for use with C/C++ (GNU Project Debugger (GDB), Valgrind, etc.)
• The ability to obtain and maintain a U.S. government issued interim secret security clearance is required prior to start.
• U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance.

Qualifications We Prefer

• Active Secret security clearance prefer.
• Experience with MATLAB development for modeling
• Experience with network programming or inter-process communication (IPC).
• Experience with CI/CD pipelines and modern DevOps practices.
• Experience with Python or other scripting languages.
• Exposure to real-time systems, embedded software, or distributed systems.
• Experience with CMake or other Software build systems
• Experience with high-performance, real-time software development
• Experience with parallel programming and hardware acceleration (e.g., multithreading, SIMD, CUDA/OpenCL)
• Experience with performance analysis, profiling, and optimization of computationally intensive applications

What We Offer

Our values drive our actions, behaviors, and performance with a vision for a safer, more connected world.

• Safety
• Trust
• Respect
• Accountability
• Collaboration
• Innovation

Clearance Information

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

Onsite

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.

Location

Huntsville, AL: https://careers.rtx.com/global/en/raytheon-huntsville,-al-location #LI-RH2 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.

Salary

The salary range for this role is 107,500 USD - 204,500 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
• holidays
• 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.

If the successful candidate resides in a U.S. territory, the appropriate pay structure and benefits will apply.

Application Window

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.

Equal Opportunity

RTX is an Equal Opportunity Employer.

Diversity Statement

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.

Company Description

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.