Our client is a globally established, product-led technology organisation currently undergoing a large-scale platform and security transformation. They offer anexcellent salary package,great benefits, and avery good team environment. Withlow attritionand asolid, experienced team, they provide anice working environmentand strongcareer progression opportunities. Having partnered with them for several years, we've seen their consistent investment in people and technology.They are hiring a senior technical leader with a strong blend of.NET expertise,IAM knowledge, andleadership experience. This role requires someone who can operate across architecture and hands-on delivery, guiding teams through a complex modernisation journey. You should be confident working inAgile environments, engaging with global stakeholders, and translating high-level strategy into clear technical direction. Strong English communication is essential.Core Responsibilities You will lead the architectural evolution of a business-critical platform, focusing on improvingscalability, security, and maintainability. This includes defining a modern target architecture and supporting the transition from legacy systems tocloud-ready solutions. As a.NET expert, you will review existing C# codebases, identify risks, and guide refactoring aligned with modern standards. You will also take ownership ofIdentity & Access Management architecture, ensuring secure authentication and authorization aligned withOAuth2, OIDC, and JWT. Collaboration is key — you will work closely with cross-functional teams across engineering, product, and infrastructure, while also supporting Agile delivery by translating architecture into clear technical tasks. You will regularly communicate with senior stakeholders, providing clear updates on progress, risks, and technical decisions.Key Skills Required Strong experience withC# and .NET architecture(modern and legacy systems) Proven expertise inIdentity & Access Management (IAM) Solid understanding ofOAuth2, OIDC, and JWT protocols Experience withplatform modernisation(cloud migration, refactoring, system upgrades) Strong background indistributed and cloud-native architectures Knowledge ofAPIs, microservices, and integration patterns Experience working inAgile (Scrum / Kanban) environments Ability to translate architecture intotechnical deliverables (epics, user stories) Strongleadership and stakeholder managementskills Excellentwritten and verbal English communicationNice to Have Experience withlarge-scale system transformation projects Exposure todatabase modernisation and data architecture Background inmentoring teams and setting engineering standards Experience working inglobally distributed teams