Upcoming Java & JVM Conferences 2026

Devoxx Belgium (Antwerp, October) is the largest community Java conference in the world (~3,500 attendees). Devoxx also runs in the UK (London), France (Paris), Poland (Kraków), Morocco, and Greece. Spring I/O (Barcelona) is the flagship Spring ecosystem event. JFokus (Stockholm) is a premier Scandinavian Java conference. GeeCON runs in Poland. KotlinConf is JetBrains' dedicated Kotlin event. JavaOne / Oracle CloudWorld cover the Oracle ecosystem. Regional Java User Group (JUG) events run in virtually every major city.

The hottest Java platform topics in 2026 are: Project Loom's virtual threads (now GA in Java 21, reshaping concurrency patterns), GraalVM native image compilation (critical for serverless and fast startup containers), Project Panama (foreign function API, vector API for SIMD), sequenced collections and pattern matching (Java 21 features), the new structured concurrency API, and JVM startup optimization for cloud workloads. Spring Boot 3.x with virtual threads and native compilation, Quarkus Reactive, and Micronaut for serverless are the practical application framework discussions.

AI integration is the fastest-growing topic at Java conferences in 2026. Spring AI provides a portable abstraction over LLM providers (OpenAI, Anthropic, Ollama) and vector stores. LangChain4j is the Java community's LangChain equivalent. Key session topics include: embedding generation and semantic search in Java, building RAG (Retrieval-Augmented Generation) pipelines with Spring AI, integrating vector databases (pgvector, Redis, Chroma) from Java, AI-assisted code generation with Java codebases, and structured output extraction from LLMs. Quarkus and Micronaut also have dedicated AI extension ecosystems.

Both. KotlinConf (organized annually by JetBrains) is the dedicated Kotlin conference and draws 1,000+ Kotlin practitioners globally. Kotlin has strong representation at Devoxx (typically 20–30% of talks), JFokus, Spring I/O, and GeeCON. Topics include Kotlin multiplatform (KMP) sharing code across Android, iOS, and server; Kotlin coroutines for async programming; Kotlin DSLs for Gradle and other build tools; and Compose Multiplatform for shared UI. If you're primarily interested in Kotlin-on-server vs Kotlin-for-mobile, the Java conferences tend to cover the former more deeply.

Java dominates JVM conference content by volume, but Kotlin has largely displaced Scala as the second JVM language in conference programs. Scala conferences (Scalar, Scala Days) still run independently with a focus on functional programming and Akka/ZIO. Groovy features at Greach (Madrid) and some DevOps events (Gradle, Spock testing). Clojure has ClojureConj and ClojureDays. For backend JVM engineers, the practical choice is Java 21+ or Kotlin — both are first-class at major JVM conferences, and the tooling, framework, and performance content transfers well between them.

Yes — QCon London and InfoQ conferences regularly feature low-latency Java tracks covering JVM tuning (GC selection, ZGC, Shenandoah), JIT optimization, off-heap memory management (Chronicle Map, Agrona), and LMAX Disruptor-style lock-free concurrency. JVMLS (JVM Language Summit) is an invite-oriented technical workshop where JVM engineers and language implementors discuss deep runtime details. The JCrete and JAlba unconferences (in Greece) attract core Java developers for open discussion sessions. Performance-focused Java practitioners also follow the OpenJDK mailing lists and attend talks by Aleksey Shipilëv, Monica Beckwith, and other JVM performance experts.