Senior C# IAM Developer - Auth0, Identity & Access Control, AWS OUTSIDE IR35 Contract: 8 months Rate: £700 - £750 OUTSIDE IR35 Location: 100% remote The Role: Working for a global, market leading B2B SaaS business, youll lead the design and implementation of secure, identity-driven backend services in a modern C#/.NET environment. Your work will centre on authentication, authorization, and secure event-driven architectures. Youll own our Auth0 integration end-to-end , ensuring our platform meets strict security, compliance, and reliability standards. This is a role for someone who thinks deeply about threat models, defence-in-depth, and secure-by-default engineering. What Youll Do: Architect and implement secure backend services in C# & .Net Own and evolve our Auth0 identity platform: tenant configuration, flows, hooks, rules, MFA, RBAC Design and maintain token-based security models (OIDC, OAuth2, JWT lifecycle, refresh strategies) Build secure event-driven and serverless components ( AWS Lambda, SNS/SQS, EventBridge ) Lead secure coding practices, code reviews, and threat modelling sessions Work closely with product and platform teams to ensure security is embedded from design to deployment Improve observability around authentication flows, anomaly detection, and abuse prevention Contribute to internal security standards, policies, and incident response readiness What You Bring: 10+ years experience building production systems in C# & .NET Deep knowledge of Auth0 (Actions, Rules, Hooks, Universal Login, MFA, RBAC, custom claims) Solid understanding of OAuth2 , OIDC , SAML , JWT , and modern identity patterns Experience with AWS serverless ( Lambda, API Gateway, DynamoDB, EventBridge ) Strong grasp of secure coding principles: input validation, secrets management, least privilege, secure session/token handling Ability to design and review threat models for distributed systems Comfortable working in high-autonomy, high-ownership environments Bonus: experience with Terraform, CI/CD security, or penetration testing Why Join Us: Work on a greenfield platform where security is a first-class concern, not an afterthought High-impact role with architectural ownership Modern stack, modern identity tooling, modern engineering culture Competitive compensation, flexible working, and a team that values technical excellence Contract: 8 months Rate: £700 - £750 OUTSIDE IR35 Location: 100% remote TPBN1_UKTJ
Senior C# IAM Developer - Auth0, CIAM, AWS - Outside IR35 employer: Smart Sourcer Limited
Join a forward-thinking company at the forefront of the data centre construction revolution, where your role as a Project Manager will be pivotal in shaping the future of AI. With a strong emphasis on employee growth and a collaborative work culture, you will have access to comprehensive training and development opportunities while working in vibrant locations like Central London and High Wycombe. Enjoy competitive remuneration and benefits, all while contributing to high-impact projects that drive innovation in engineering and infrastructure.
