I'm Building a Production-Grade Spring Boot + React App, One Feature a Day (Day 1) (opens in new tab)

I just finished a 50-day "new tech every day" series. For the next 50 days I'm doing the opposite: ONE production-grade app, one feature a day — and building both the Spring Boot backend AND the React frontend each day. This is Day 1. The app: OrderHub, an e-commerce order-fulfillment backend that will grow into a real event-driven microservices system (Redis → Kafka → sagas → Kubernetes). But today it starts where every solid service starts: a clean REST API with a proper layered architectur...