Let me clarify this with an example from my recent experience at Wipro. I was responsible for migrating a suite of SOAP APIs to REST APIs for a major banking client. The goal was to modernize the integration layer, improve performance, and make the system easier to maintain in the long run. To ensure scalability, I designed the REST APIs using a microservices approach, where each service handled a specific business function. This allowed us to scale individual components based on demand. For deployment, we used Docker containers orchestrated with Kubernetes, which helped with automatic scaling and high availability, especially during peak loads.On the maintainability side, I followed a layered architecture. The controller layer handled incoming requests, a separate validation layer checked input data, and the business logic was kept isolated from data access code. This separation made it easier to update or troubleshoot specific parts without affecting the whole system. I also made sure to document the APIs thoroughly using Swagger, which helped both our team and external partners understand and use the APIs effectively.Additionally, I implemented automated unit and integration tests to catch issues early and ensure that future changes wouldn’t break existing functionality. Regular code reviews and close collaboration with QA and DevOps teams further contributed to a robust and maintainable solution. What I mean is, by combining modular design, containerization, good documentation, and automated testing, we achieved both scalability and maintainability for the REST APIs, which made a significant positive impact on the project’s success.