Senior Software Engineer - Security Systems

Senior Software Engineer — Security Systems Description Mission Critical Applications Limited (MCA) is a UK SME specialising in high-integrity applications for safety- and security-critical systems, with expertise in embedded and real-time systems, formal methods, secure systems (including CHERI) and networks. The role This is a great opportunity to join MCA on a new R&D project. You'll be a core member of a small engineering team building a network security guardian, taking it from early design through to a working prototype. What you'll be doing Designing and implementing protocol-handling and session-management logic in Python and C/C++Building and testing components on Unix/Linux-based CHERI systemsIntegrating components into the full system and testing against third-party network equipment Essential Strong C/C++ development experience on Unix/Linux platformsStrong Python development experience, especially protocol-level communicationsExperience with network protocol implementation or low-level systems programming Desirable CHERI experience (or experience with capability-based / memory-safe architectures) is highly desirableComfortable working with AI, ideally with experience of co-development with AI Key details Remote (UK-based), with occasional travel for events/meetingsContract or permanent employment consideredFull-time or part-time (around 3 days a week expected)Starting October or November 2026, running to August 2027, with the potential to continue beyond thatReports to the Principal InvestigatorCompensation: competitive, commensurate with experience, discussed directly with candidates What we offer Remote, flexible working within a small, highly experienced engineering teamHands-on work with CHERI capability-based hardware, a UK-led secure computing technologyA new R&D project taken from early design through to a working prototypeThe potential to continue with MCA beyond the initial engagement Eligibility You must be based in the UK and have the right to work in the UK. Any offer is subject to right-to-work checks and satisfactory references, and may be subject to further security checks given the nature of the work. How to apply Send a CV and covering letter to info@mca-ltd.com outlining relevant experience, quoting reference MCA-SWE-2026. Applications are reviewed on a rolling basis, and the role closes once a suitable candidate is found. MCA is an equal opportunities employer. We welcome applications from all suitably qualified people, whatever their background. If you need any adjustments to the application or interview process, please tell us when you apply. We use your information only to assess your application, handle it in line with UK data protection law, and delete it if your application is unsuccessful unless you agree we may keep it for future roles.