Designing Production Microservices with Spring Boot 4: Build Scalable Java Services Cloud, PostgreSQL, Security, Kafka, Docker, Kubernetes, Testing, and Observability

Build microservices that are ready for production-not just impressive in a diagram.Designing a microservices system is relatively easy. Designing one that can survive real traffic, network failures, database contention, deployment changes, security threats, and operational incidents is a different challenge.Designing Production Microservices with Spring Boot 4 is a practical guide to building scalable, resilient, and maintainable Java microservices using the modern Spring ecosystem.Rather than presenting disconnected examples, the book develops Northstar, a realistic commerce platform, throughout the chapters. You will see how architectural decisions evolve as the system introduces independent services, service-owned databases, synchronous communication, event-driven workflows, security, containers, Kubernetes, testing, observability, and production operations.Inside, you'll learn how to: - Design effective service boundaries and domain ownership- Build production-grade services with Spring Boot 4 and Java 21- Manage service-owned data with PostgreSQL, JPA, Flyway, transactions, and concurrency controls- Implement reliable HTTP communication with timeouts, retries, circuit breakers, bulkheads, and idempotency- Use Spring Cloud Gateway, configuration, and service discovery- Build event-driven workflows with Apache Kafka- Handle distributed consistency using sagas, transactional outbox, compensation, and reconciliation- Secure services with Spring Security, OAuth 2.0, JWT, scopes, and service-to-service identity- Test real infrastructure with JUnit and Testcontainers- Build secure, reproducible Docker containers- Deploy and operate services with Kubernetes- Implement production observability with Actuator, Micrometer, OpenTelemetry, metrics, logs, traces, and SLOs- Diagnose performance bottlenecks and plan for scaling and capacity- Assemble the individual services into an operable production microservices platformThis book focuses on the decisions that matter when systems fail: ownership, failure boundaries, idempotency, recovery, compatibility, security, deployment safety, and operational visibility.Whether you're a Java developer, Spring Boot engineer, backend developer, software architect, or platform engineer, this book provides a practical path from individual Spring services to a disciplined production microservices architecture.Move beyond basic REST APIs and learn how production microservices are actually designed, tested, deployed, observed, and operated.