Overview
In this role as a Senior C# IAM Developer, you will be responsible for leading the design and implementation of secure identity-driven backend services for a major B2B SaaS platform. Collaborating closely with product and platform teams, you will ensure robust authentication and authorization processes while maintaining compliance with security standards. This remote position offers the opportunity to work on a greenfield platform with a focus on modern security practices and architecture.
Responsibilities
- Architect and implement secure backend services in C# & .NET.
- Own and evolve the Auth0 identity platform, including tenant configuration and flows.
- Design and maintain token-based security models (OIDC, OAuth2, JWT lifecycle).
- Build secure event-driven and serverless components using AWS technologies.
- Lead secure coding practices, code reviews, and threat modeling sessions.
- Collaborate with product and platform teams to integrate security into designs.
- Enhance observability of authentication flows, anomaly detection, and abuse prevention.
- Contribute to internal security standards, policies, and incident response readiness.
Requirements
- 10+ years of experience building production systems in C# & .NET.
- Deep knowledge of Auth0 (Actions, Rules, Hooks, Universal Login, MFA, RBAC).
- Solid understanding of OAuth2, OIDC, SAML, JWT, and modern identity patterns.
- Experience with AWS serverless technologies (Lambda, API Gateway, DynamoDB, EventBridge).
- Strong grasp of secure coding principles including input validation and secrets management.
- 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.