Platform Architect Design Lead - Inside IR35 - SC ClearedThe Platform Architect Design Lead will provide architectural leadership for a highly secure defence programme, shaping the design and evolution of complex digital and technology platforms supporting next-generation defence capability.The role operates as the design authority for platform architecture, ensuring solutions are secure by design, resilient, and aligned to programme objectives, defence standards and delivery constraints. This is a senior, hands-on role working across engineering, cyber security and programme leadership teams within a classified environment.Key ResponsibilitiesAct as the design authority for platform architecture across the programmeDefine and maintain target and transition architectures for secure platformsLead architectural design activities across infrastructure, platform and integration layersEnsure platforms are secure by design and aligned to programme risk appetiteProvide architectural oversight across design reviews, assurance gates and delivery phasesCollaborate closely with engineering, cyber security and assurance teamsSupport architectural decision-making across Legacy, prototype and evolving platformsProduce clear architectural artefacts, standards and design documentationManage architectural risks, trade-offs and technical debt in complex environmentsRequired Experience andamp; CapabilityProven experience operating as a Lead or Principal Platform Architect on complex programmesS