Java Spring Boot Best Practices v2.0

Production-ready Spring Boot guide. Updated for Spring Boot 3.5.x / 4.0.x, Java 17+ (optimized for 21+).

What's New in v2.0

• Java Records as DTOs (immutable by default)
• Virtual Threads for high-concurrency I/O (spring.threads.virtual.enabled=true)
• ProblemDetail (RFC 7807) for standardized error responses
• RestClient replaces RestTemplate (fluent, synchronous)
• Structured Logging built into Spring Boot 3.4+
• Testcontainers as primary integration testing strategy (replaces H2)
• Observability with Micrometer Observation API
• Docker Compose integration for dev environments
• Sealed classes for exception hierarchies
• GraalVM Native Image / CDS awareness

Quick Start Checklist