Ever wondered why your Spring Boot application slows down under load? In this talk, I'll walk through real-world performance bottlenecks I've encountered in production systems and the techniques used to resolve them. We'll cover JVM tuning, connection pool optimization, async processing with CompletableFuture, and caching strategies with Redis. You'll learn how to use profiling tools like JFR and VisualVM to identify issues before they impact users, and discover practical tips for writing performant Spring Boot code that scales.

Kafka Streams has transformed how we build real-time data processing applications, but getting started can be daunting. This session demystifies Kafka Streams by building a complete real-time analytics pipeline from scratch. We'll explore stateful transformations, windowing operations, joins, and error handling patterns. I'll share lessons learned from running Kafka Streams in production at scale, including state store management, rebalancing strategies, and monitoring approaches. Whether you're new to stream processing or looking to level up your Kafka skills, this talk provides practical insights you can apply immediately.

After migrating multiple monoliths to microservices architectures, I've seen what works in theory versus what works in practice. This talk covers essential microservices patterns including circuit breakers, service discovery, distributed tracing, and saga patterns for managing distributed transactions. I'll share war stories about common pitfalls like the distributed monolith anti-pattern, over-engineering, and premature decomposition. You'll walk away with a pragmatic framework for deciding when microservices make sense and how to implement them effectively using Spring Cloud, Resilience4j, and modern observability tools.

Java 21's virtual threads represent the biggest shift in Java concurrency since the introduction of CompletableFuture. In this session, we'll explore how virtual threads work under the hood and when they provide real benefits over traditional threading models. Through live coding examples, I'll demonstrate migrating a thread-per-request web application to use virtual threads, measuring the performance improvements and discussing the gotchas. We'll also touch on structured concurrency and scoped values. If you're still writing Java 8 or 11 code, this talk will show you why it's time to upgrade.

Code reviews are one of the most powerful tools for mentoring developers, yet they're often done poorly or treated as a mere checkbox. In this talk, I share techniques I've developed over years of leading development teams to turn code reviews into learning opportunities. We'll discuss how to give constructive feedback that improves code quality without demoralizing developers, how to create a review culture that encourages knowledge sharing, and how to use reviews to establish coding standards. I'll also cover tools and workflows that make reviews more efficient. Aimed at senior developers looking to level up their mentoring game.