Define and document API specifications, endpoints, data models, and protocols (REST, GraphQL). Build and implement APIs using Java and Python. Ensure seamless integration of APIs with internal and external systems. Write and debug unit, integration, and end-to-end tests for APIs. Create and maintain comprehensive documentation for API consumers. Implement security best practices for data and services. Monitor and optimize API performance, scalability, and reliability. Manage API versions and ensure backward compatibility. Work closely with development teams and stakeholders. Provide ongoing support and troubleshoot issues.