Senior Software Engineer (C# / .NET) - Contractual Role

Working at Tech Holding isn't just a job, it's an opportunity to be a part of something bigger. We are a full-service consulting firm that was founded on the premise of delivering predictable outcomes and high-quality solutions to our clients.  Our founders and team members have industry experience and have held senior positions in a wide variety of companies – from emerging startups to large Fortune 50 firms – and we have taken our combined experiences and developed a unique approach that is supported by the principles of deep expertise, integrity, transparency, and dependability.

About the Role
We are looking for a skilled Senior C# / .NET Engineer to support a critical platform
security and modernization initiative. This role focuses on backend/API enhancements,
security implementation, and system reliability improvements in alignment with Azure-
based infrastructure and data protection standards.

Key Responsibilities

 Design and develop secure backend services and APIs using C# / .NET.
 Implement authentication and authorization mechanisms (SSO, RBAC, OAuth,
JWT).
 Integrate applications with Azure Active Directory (Entra ID).
 Remove hardcoded secrets and integrate with Azure Key Vault.
 Implement audit logging and monitoring hooks across services.
 Build and enforce secure API communication standards.
 Implement PII masking and secure data handling logic in applications.
 Secure and optimize third-party integrations (Stripe, SendGrid, Twilio, etc.).
 Support environment separation and deployment improvements.
 Collaborate with DevOps and DB teams on security, DR, and compliance
initiatives.
 Participate in debugging, incident resolution, and root cause analysis.

Requirements:

 5+ years of experience in C# / .NET development.
 Strong experience with ASP.NET Core, Web APIs, and microservices
architecture.
 Experience implementing authentication & authorization (OAuth, JWT, SSO).
 Hands-on experience with Azure services, especially Azure AD (Entra ID).
 Experience with secure coding practices and data protection.
 Familiarity with API integrations (Stripe, SendGrid, etc.).
 Experience with logging frameworks and monitoring tools.
 Understanding of CI/CD pipelines and cloud deployments.
 Strong debugging, problem-solving, and communication skills.

Good to Have
 Experience with containerization (Docker, Kubernetes)