Responsibilities: Design, develop, and maintain backend services and RESTful APIs using Node.js and Express.js Implement serverless architectures using AWS Lambda, API Gateway, DynamoDB, and Step Functions Implement secure authentication and authorization (e.g., using Cognito, OAuth, JWT) Collaborate with frontend developers, DevOps, and QA to deliver scalable, performant solutions Optimize application performance, ensure fault tolerance, and handle error logging/monitoring (e.g., CloudWatch, X-