API Developer (Python, .NET, AWS)

We are seeking a full-stack backend API Developer for an onsite contract (W-2) engagement in Atlanta, GA. You will design, build, and support RESTful services and integrations across a mixed Python and .NET estate running on AWS, working closely with product, front-end, and platform teams. Responsibilities: - Design and develop secure, well-documented REST APIs and microservices in Python and C#/.NET - Build and consume integrations between internal services and third-party platforms - Deploy and operate services on AWS using Lambda, API Gateway, ECS/EKS, S3, SQS/SNS, and RDS/DynamoDB - Write unit, integration, and contract tests; maintain high code quality through reviews - Implement authentication and authorisation (OAuth2, JWT), rate limiting, and API versioning - Troubleshoot production issues, and improve performance, logging, and observability - Contribute to CI/CD pipelines and participate in Agile ceremonies Work mode: This is a 100% onsite role in Atlanta, GA — no remote or hybrid option. Employment: Contract on our W-2 only. Candidates must hold independent work authorisation (no third-party employer or sponsorship arrangement). Rate depends on experience. Requirements: Must have: Python Must have: .NET (C#, ASP.NET Core / .NET Core) Must have: AWS Must have: REST API design and development Hands-on experience with Python web frameworks (FastAPI, Flask, or Django REST Framework) AWS services: Lambda, API Gateway, ECS/EKS, S3, SQS/SNS, CloudWatch, RDS/DynamoDB API security: OAuth2, JWT, API keys, throttling, and versioning strategies SQL and NoSQL databases; performance tuning of queries and endpoints OpenAPI/Swagger documentation and contract testing Docker, Git, and CI/CD pipelines Automated testing (pytest, xUnit/NUnit) and Agile/Scrum delivery Good to have: Azure or GCP exposure, event-driven and messaging architectures, GraphQL Bachelor's degree in Computer Science, Engineering, or a related field Work mode: onsite in Atlanta, GA (mandatory) Employment: our W-2 only — independent work authorisation required, no third-party or sponsorship