Title: Research Software Engineer , Formal Methods (Hybrid) Location: Arlington United States Job Description: Date Posted: 2026-04-01 Country: United States of America Location: US-MA-CAMBRIDGE-BBN06 ~ 10 & 50 Moulton St ~ MOULTON B6 Position Role Type: Hybrid 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: Top Secret Security Clearance Status: Active and existing security clearance required after day 1 At RTX, the world 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. Join us and help shape the future of aerospace and defense. RTX BBN Networking and Cyber Technologies group is looking for a Research Software Engineer, Formal Methods with strong software development skills and an interest in security and resilience of large-scale dynamic systems. In this position, you will contribute strong software development skills and apply reasoning and formal methods techniques to significantly enhance security and resilience of large dynamic systems. This position offers the opportunity to shine as a lead developer of an exceptional team while building core technologies for improving processes, networks, protocols, and systems. You will develop software to support models that analyze networks and complex processes, improve the collective understanding of such systems, and increase their performance. You will contribute to and work alongside extraordinarily talented individuals. What You Will Do - Program and test software and systems in Python, C, C++, or Java, as well as using logic programming languages. - Design and develop formal (using mathematical logic) or informal models and specifications of protocols and systems. - Develop algorithms for analyzing systems to understand how and when they work or break, and how to make them more secure and resilient. Working knowledge applying formal methods techniques such as model checking and theorem proving are highly desirable. - Apply critical analyses to results to validate technical hypotheses and inform next steps. - Advance network security research at BBN. - Own projects or large components of projects. - Distinguish BBN and yourself to customers by leading and performing cutting edge research. - Travel up to 10%; candidates should expect that they may be required to travel to a BBN, RTX, teammate, or customer site for meetings or other business-related activities. Qualifications You Must Have - Typically requires: A University Degree in Computer Science, Computer Engineering, Electrical Engineering, Mathematics, or Physics or equivalent experience and minimum 5 years prior relevant experience, or an Advanced Degree in a related field and minimum 3 years experience. - Minimum 3 years' experience with multiple software development tools and languages, including Python and either C/C++ or Java. - Prior experience with Formal Methods, preferably with the application and scaling of formal methods techniques (e.g. model checking, model measuring, and theorem proving). - Prior experience with mathematical logic and logic programming. - Prior experience with networking fundamentals. - Prior experience in systems security. - Ability and willingness to obtain a Top Secret Clearance within a year. Qualifications We Prefer - Experience with Formal Methods, specifically with the application and scaling of formal methods techniques such as model checking, model measuring, and theorem proving. - PhD degree. - Experience writing logic for SAT, SMT solvers. - Experience with Python and/or shell scripting. - Experience writing proposals, capture. - Experience in Networking and protocols (TCP/IP stacks, wire-level protocols, RF communications, BGP, etc.). Location Please ensure the role type defined below is appropriate for your needs before applying to this role. This position is classified as: - Hybrid: Employees who are working in Hybrid roles will work regularly both onsite and offsite. Ratio of time working onsite will be determined in partnership with your leader. - Hybrid from one of the following locations: Columbia, MD - Arlington, VA - Cambridge, MA - Relocation assistance will be available. To help you achieve your goals, BBN will provide: - We invent new science by applying cross-discipline techniques in new ways. - Network and Cyber Technologies group anticipates the future of communications from applied physics to fundamental analysis of large application systems. - A strong leadership team well-versed in Government Research & Development. - A collaborative and collegial environment to push state-of-the-art research. - Technically competent pool of research scientists who are willing to mentor, listen, and help you refine your research vision and goals. - Business Development, Programmatic, Contracting, Finance, and HR support. - Access, through RTX, to opportunities that help transition your research and ultimately see it fielded. Learn More & Apply Now Whether you're just starting out on your career journey or are an experienced professional, we offer a robust total rewards package with compensation; healthcare, wellness, retirement, and work/life benefits; career development and recognition programs. Some of the benefits we offer include parental (including paternal) leave, flexible work schedules, achievement awards, educational assistance and child/adult backup care. 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 86,800 USD - 165,200 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. 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