G1, ZGC, Shenandoah, ... with all these GCs in Java, which one do I choose?

It feels like with every new Java release, there are more and more Garbage Collectors (GCs) coming with more and more options. We hear cryptic phrases like: "Oh, awesome, ZGC became generational while Shenandoah isn't" or "Did you heard how Netflix reduced their tail latencies with ZGC?"

Naturally, it leaves us with a ton of questions:

• What on earth are they talking about?
• What exactly is ZGC?
• If this ZGC is so magical, why are there even other GCs left in Java anyway?
• Why do we only ever talk about different GCs for Java, but never for Go or JavaScript? Can the Java folks make up their minds and pick one?
• And what about native? Do we even need a GC there?

Whether you are a Java developer or just plain curious, everyone is welcome! We will trace the journey from the creation of Java all the way to the present day to understand why we need a GC and why it isn't a solved problem. We will also take a tour of the various GCs, their evolutions, their strengths, and their weaknesses. (Spoiler alert: ZGC is not the one GC to rule them all).

By the end of this talk, you will know exactly when to use which GC so you can find the perfect fit for every project, every application, and every environment.