In a microservices environment, services scale up and down dynamically. You can’t hardcode IP addresses — a service running on 10 pods today has 10 different addresses. Service discovery solves this: services register themselves, and clients look up live instances by name. What Service Discovery Does Without service discovery: Order Service → http://192.168.1.45:8081/api/inventory ← hardcoded, breaks when IP changes With service discovery: Order Service → "inventory-service" → Eureka → [192.168.1.45:8081, 192.

Building microservices requires more than splitting a monolith into services. You need service discovery, a gateway to route traffic, centralised configuration management, and resilience patterns to handle inevitable failures. Spring Cloud provides all of this as a cohesive stack. This guide builds a complete microservices architecture from scratch: Eureka for service discovery, Spring Cloud Gateway for routing, Spring Cloud Config Server for centralised config, and Resilience4j for circuit breakers and retry.