Microservices Architecture & API Design is a comprehensive course designed for software developers and architects who want to build scalable, maintainable, and independent services. The course starts by comparing monolithic vs. microservices architectures, exploring when and why to use microservices for agility and resilience. Learners understand the core principles of microservices including loose coupling, high cohesion, decentralized governance, domain-driven design (DDD), and fault isolation. The course then transitions into the design, development, and deployment of microservices. Learners explore service decomposition strategies, bounded contexts, and the role of APIs in enabling communication between services. RESTful API design is covered in detail, along with best practices for URL structuring, versioning, authentication, and error handling. The course introduces tools like Swagger/OpenAPI for API documentation and Postman for testing. Advanced patterns such as API gateways, service discovery, circuit breakers, and event-driven communication are explored using technologies like Spring Boot, Node.js, Docker, and Kubernetes. Learners also implement asynchronous communication via message brokers like Kafka and RabbitMQ. Topics such as data consistency, distributed transactions (SAGA pattern), logging, tracing (OpenTelemetry), and CI/CD pipelines are addressed. By course end, learners will be able to design, build, and maintain robust microservice ecosystems capable of scaling independently and evolving with business needs.