Senior Software Engineer ATMS

Prattwhitney; Harlow; Hybrid; GBP 75,000 - 90,000; Full time

Benefits offered by this job

Competitive salary

Pension scheme

Life assurance

Holiday entitlement

Bonus scheme

Job summary

RTX ATMS Software team in Raytheon seeks a Senior Software Engineer to design, develop, and test real-time embedded systems for global customers. Work in an Agile, hybrid role in Harlow, UK, with on-site requirements.

You will leverage C/C++/C#, UML and RTOS, contributing to internal R&D and supporting the product life cycle across the software stack.

Qualifications

• Essential: hands-on software development experience in a team
• Experience with C/C++/C# for real-time embedded systems
• Knowledge of UML in software design and other methodologies
• Real-Time Embedded SW programming experience and RTOS knowledge
• Familiarity with low-level communication protocols (Ethernet, Serial, PCI)
• Desirable: 2:1 degree in CS; Agile/SCRUM/DevOps experience

Responsibilities

• Design and develop product functionality and performance improvements.
• Act as contributor and reviewer at gate/design reviews.
• Analyse and resolve defects in response to service requests and incidents.
• Validate design artefacts from internal teams or subcontractors.
• Provide input to configuration, safety and quality management.
• Document design and advise on product support material.
• Develop test plans and methodologies to meet quality standards.
• Lead continuous technical improvement and re-architecting activities.

Skills

C/C++/C#

RTOS

Embedded software

Networking protocols

Education

2:1 degree in computer science

Tools

UML

Job description

Job Details

Date Posted: 2026-09-16 Country: United Kingdom Location: Harlow, Essex Position Role Type: Hybrid

Benefits: £: Competitive salary, Contributory Pension Scheme (up to 10.5% company contribution), 6 times salary ‘Life Assurance’ with pension, 25 days holiday (increasing with service) + statutory public holidays, plus opportunity to buy and sell up to 5 days (37hr), Company bonus scheme 4% (discretionary), Flexible Benefits scheme with extensive salary sacrifice schemes, including Health Cashplan, Dental, and Cycle to Work amongst others, Enhanced sick pay, Enhanced family friendly policies including enhanced maternity, paternity & shared parental leave.

Work Culture: 37hr working week, although hours may vary depending on role, job requirement or site-specific arrangements. Early 1.30pm finish Friday, start your weekend early! Remote, hybrid and site based working opportunities, dependant on your needs and the requirements of the role. Up to 5 paid days volunteering each year. Flexible working culture focused on output, with more formal flexible working arrangements on request (assessed subject to role) - please highlight any requests to the Talent Acquisition team.

Function: Engineering Location: Harlow (Hybrid with 4 days a week on site) Clearance: SC Eligible Hours: 37 hours per week with early finish on Fridays.

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.

Summary of Role

Raytheon’s ATMS (Air Traffic Management Systems) Software team is seeking talented, enthusiastic and innovative individuals that thrive within an Agile eco-system to deliver world class solutions that make the world a safer place. Become a part of something greater than yourself by bringing your best in collaboration with other motivated and talented individuals across a diverse set of backgrounds and skill sets.

Main Duties

As a Senior Software Engineer you will work within our existing software engineering team bringing your experience of real-time embedded software engineering to design, develop, integrate and test systems software to support our worldwide customer base. You will also have opportunity to work on exciting internal R&D projects to support the next generation of ATMS systems.

• Design and develop product functionality, user interfaces and performance improvements.
• Key contributor & reviewer at gate & design reviews.
• Act as Subject Matter Expert as part of a wider software and systems engineering group to analyse and resolve software and system defects in response to service requests, incidents, problems and events.
• Validating and verifying the design artefacts from internal teams or subcontractors.
• Provide input to configuration, safety and quality management as appropriate.
• Document design and advise on product support material.
• Investigate product issues and develop solutions to customer problems.
• Develop test plans and methodologies to ensure product meets Raytheon quality standards.
• Lead continuous technical improvement and re-architecting activities.
• Assist in updating software design artefacts.
• Interfacing with COTS vendors for technical support.
• Provide technical support (covering the entire software lifecycle) to Raytheon programmes delivering new capability.

Candidate Requirements

• Essential: Relevant years' active, hands-on software development experience, working in a Team environment
• Relevant years’ experience with C/C++/C# language
• Experience in the use of UML in software design and other methodologies
• Real-Time Embedded SW programming experience
• RTOS knowledge
• Knowledge of low-level communication protocols, Ethernet, Serial, PCI Bridge
• Hands on fault investigation experience in embedded code environment
• Use of tools in software configuration management, requirements definition, high-level and detailed design, defect reporting
• Desirable: Min 2:1 degree in a computer science or related subject
• Experience working in an Agile/SCRUM/DevOps delivery model.
• Knowledge of Radar systems.
• Hands‑on experience in reverse engineering a mature system to take advantage of a modern technology development in hardware, software and firmware.
• Competency with design patterns and their application to solve complex problems.
• #LI-MF1 RTX adheres to the principles of equal employment. All qualified applications will be given careful consideration without regard to ethnicity, color, religion, gender, sexual orientation or identity, national origin, age, disability, protected veteran status or any other characteristic protected by law.

Equal Employment Opportunity

RTX adheres to the principles of equal employment. All qualified applications will be given careful consideration without regard to ethnicity, color, religion, gender, sexual orientation or identity, national origin, age, disability, protected veteran status or any other characteristic protected by law.

Company Overview

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.