We are looking for a Senior Platform Engineer to play a key role in the design, delivery, and evolution of our platform engineering capabilities. This role combines deep technical expertise with hands-on delivery and cross-functional collaboration. You will contribute to platform architecture, engineering standards, and operational excellence across hybrid environments, supporting mission-critical systems within the Defence and Security sector. Key Responsibilities Platform Engineering & Delivery Design and implement scalable, secure, and maintainable platform solutions across cloud and on-premise environments. Contribute to the development and governance of CI/CD pipelines, ensuring consistency and efficiency. Support the implementation of monitoring, observability, and incident response frameworks. Operational Excellence Collaborate with SRE and operations teams to ensure platform reliability, performance, and resilience. Participate in incident response and root cause analysis, driving continuous improvement. Technical Leadership Act as a subject matter expert in platform technologies, guiding engineering decisions and best practices. Mentor junior engineers and contribute to a culture of technical excellence and knowledge sharing. Innovation & Collaboration Evaluate emerging technologies and contribute to platform evolution and innovation. Work closely with cross-functional teams to translate business requirements into platform capabilities. Participate in architecture reviews, governance forums, and strategic planning sessions. Qualifications & Experience Strong experience in platform engineering, DevOps, or infrastructure development. Proficiency in Kubernetes, CI/CD tooling, cloud platforms (AWS, Azure, GCP), and Infrastructure as Code. Demonstrated ability to deliver complex platform solutions in hybrid environments. Solid understanding of platform security, compliance, and operational tooling. Excellent communication and collaboration skills. Experience in regulated environments (e.g., Defence, Security) is highly desirable. Desirable Skills Certifications in cloud platforms or DevOps practices. Experience with automation frameworks (e.g., Terraform, Ansible). Exposure to platform governance and architecture forums. Familiarity with incident management and operational support processes. Eligible for SC clearance; UK sole nationals only. Willing to apply for DV Some international travel may be required Why SiXworks? SiXworks is a leading provider of secure digital solutions, specialising in digital experimentation and focused on fail-safe-fast cutting-edge technology solutions deployed in highly secure environments. We are unified in our mission to accelerate innovation and adoption of secure, digital technology to improve the operational agility of Defence and National Security. This is an exciting time for us, we have ambitious plans for continued growth and development, and we are seeking to add brilliant, experienced, motivated, and passionate people to our team to work with us on this journey. Why join SiXworks? SiXworks’ expertise includes Secure-by-Design, cloud computing, advanced network and infrastructure design, rapid application development, cross-security domain systems, multi-tenanted High-Performance Compute, multi-source data platforms, cyber vulnerability mitigation, and intelligence systems. We provide supplier-agnostic, technical, and business consultancy to customers while championing open-source and best-of-breed technologies. What can we offer in return? SiXworks offers a unique work culture around our core principles Agility, Security, Innovation, Quality, Collaboration and Inclusivity. Together, these six principles form SiXworks' NORTH STAR, guiding the organisation towards success. Due to the secure nature of the position and working environment, you must have, or be eligible to obtain Security Clearance. SiXworks is an IBM subsidiary which has been acquired by IBM and will be integrated into the IBM organisation. SiXworks will be the hiring entity. By proceeding with this application, you understand that SiXworks will share your personal information with other IBM subsidiaries involved in your recruitment process, wherever these are located. More Information on how IBM protects your personal information, including the safeguards in case of cross-border data transfer, are available here: https://www.ibm.com/privacy A word on UK Security Clearance Due to the secure nature of the position and working environment, you must have, or be eligible to obtain Security Clearance. More details relating to UK Security Clearance can be found here: United Kingdom Security Vetting (UKSV) is the main UK government provider of security clearances. What to do next? If you are interested in the above, please apply using the link provided. Notice SiXworks recognises the benefits of Reserve service to Country, Company and individual. We support Reservists and actively encourage them to apply. We are not considering submissions from agencies.