The Open-Source Java Stack Nobody Talks About: Micronaut, Quarkus, Helidon, Javalin

Java has quietly undergone a revolution where modern open-source frameworks like Micronaut, Quarkus, Helidon, and Javalin are redefining how we build cloud-native services. Yet most developers still default to Spring Boot without realizing how powerful (and lightweight!) these alternatives have become.

This talk demystifies the “other” Java frameworks, what problems they solve, how they differ in startup time, memory usage, developer experience, native image support, and real-world production readiness.
We’ll compare architecture philosophies, DI mechanisms, reactive vs imperative models, cloud support, and the trade-offs each framework brings.

You’ll walk away with a clear mental map of when to choose which framework, how they perform under load, and where each one fits in a modern microservice or serverless environment. Whether you're a backend engineer, platform engineer, or exploring JVM alternatives for your next project, this talk will help you unlock the full potential of the open-source Java ecosystem, beyond the usual suspects.

• Understanding of modern openSource Java landscape - How micronaut, quarkus, helidon & javalin differ in architecture, DI, performance & philosophy

• When to use which framework - A practical decision matrix based on use case: microservices, serverless, reactive systems, APIs

• Native Image & Performance Insights - How each framework handles GraalVM, cold starts, memory footprint and real-world benchmarks

• Production considerations - Ecosystem maturity, observability, debugging, testing, cloud-native intergrations

• Actionable Guidanace - How to adopt or migrate to one of these frameworks and how they fit into modern FOSS driven archtiecture

P.S. @Reviewers: Most of the content is from my work experience over the last 8 years in the industry. I have been a backend engineer with Java, Spring Boot, Micronaut, Kafka and all the related stack around these.
If you are looking primarily for blog posts, then no, I have never been a blogging person. I have delivered talks in institutions and community meetups alike.