Build event-driven microservices with Spring Boot and Apache Kafka. Covers producer/consumer patterns, event schemas, error handling with dead letter topics, exactly-once semantics, Testcontainers for Kafka testing, and a complete order processing pipeline.

Build modern, interactive UIs with Spring Boot and HTMX — no React, no Angular, no build step. Covers hx-get, hx-post, hx-swap, fragment rendering with Thymeleaf, and why this approach is gaining traction for internal tools and CRUD apps.

Structure Spring Boot applications using Hexagonal Architecture. Covers ports (interfaces), adapters (implementations), domain isolation, dependency inversion, and how to test each layer independently.

Build high-performance microservices with Spring Boot and gRPC. Covers Protocol Buffers, unary and server-streaming RPCs, the grpc-spring-boot-starter, error handling, deadlines, and performance comparison with REST.

Build flexible APIs with Spring Boot and GraphQL. Covers schema-first design, @QueryMapping, @MutationMapping, N+1 prevention with DataLoader, error handling, and when GraphQL beats REST.

Find your Spring Boot application's breaking point with Gatling. Covers writing simulations, injection profiles (ramp, constant, stress), assertions, HTML reports, CI integration, and interpreting results to find bottlenecks.

Master database schema migrations with Spring Boot and Flyway. Covers versioned migrations, repeatable migrations, migration naming, rollback strategies, multi-environment setup, team workflows, and Flyway vs Liquibase comparison.

Decouple deployment from release with feature flags in Spring Boot. Covers Togglz setup, activation strategies (gradual rollout, user-based, time-based), runtime toggling, A/B testing, and production safety patterns.

The definitive guide to error handling in Spring Boot. Covers @ControllerAdvice, ProblemDetail (RFC 7807), custom exception hierarchies, validation errors, async error handling, WebSocket errors, and a production-ready error response strategy.

Add powerful full-text search to Spring Boot with Elasticsearch. Covers document mapping, Spring Data ElasticsearchRepository, custom queries, fuzzy matching, highlighting, aggregations, and production indexing strategies.