API Technical Lead

Job Title: API Technical Lead — Payments Platform Modernization Location: Alpharetta, GA or Berkeley Heights, NJ (Hybrid – 3 days onsite) Employment Type: Contract Job Description Domain: Payments / Financial Services Primary stack: .NET Core / ASP.NET Core / C# Cloud: Azure Experience: 12–15 years hands-on, with a minimum of 8 years as an API Lead Location:—Alpharetta, GA or Berkeley Heights, NJ- 3 days per week onsite, Alpharetta preferred About the Role We are hiring an API Technical Lead to own API architecture, design and implementation for a large-scale payments platform modernization program. This is a hands-on role. The successful candidate will lead the API workstream while continuing to write, review and debug code. They will work within the client's established Architecture Decision Record framework, govern design quality across the API estate, and take accountability for the end-to-end integrity of the API layer — including the observability and security contracts that downstream systems depend on. The role demands breadth of understanding across the full stack — from front end through gateway and proxy layers to backend services and cloud infrastructure — combined with the depth to identify a design defect and challenge it. The platform is built on .NET Core and ASP.NET Core across both monolithic and microservices architectures. AI assisted engineering is central to the modernization approach: the successful candidate will use GitHub Copilot and Claude Opus for forward engineering — code generation and modernization — and reverse engineering — code understanding, documentation and refactoring — and will take accountability for validating what those tools produce. Must-Have Requirements .NET & Core Engineering • 12–15 years of hands-on engineering experience, including a minimum of 8 years as an API Lead. • Strong hands-on expertise in .NET Core, ASP.NET Core and C#. • Delivery experience across both monolithic and microservices-based .NET applications. • Proficiency with Git version control. • Experience working in global delivery or offshore engagement models.