The author pivoted from AWS API Gateway to Spring Gateway for the DemoBanking App to avoid costs and stay within the Spring ecosystem. This second installment details the initial microservices—User, Account, and Transaction—each with its own PostgreSQL database schema and structured endpoints. The project uses a docker-compose setup for local development.

Choosing Spring Gateway simplifies configurations and makes the repo runnable for anyone. The architecture follows a Saga Orchestration pattern to manage distributed transactions, avoiding tight coupling. Instead of direct database relationships, the system uses an event-driven cache updates pattern with Apache Kafka for data sharing between services, preserving microservice autonomy.

Next, the developer plans to implement the API Gateway, add exception handling, and apply the Kafka-driven cache pattern. This approach mirrors real-world banking systems where resilience and loose coupling are critical. The project offers a practical template for developers learning to build secure, distributed applications without vendor lock-in.