alt Hacker News> I use Java every day but just to point out that your info about Go‘s GC seems out of date.
I'm well aware that Go's GC has improved, but the moving algorithm was designed not just to be fast for a GC, but to be faster than no GC. So Go's new GC is good - for a mark and sweep collector. But it can't compete with a moving collector (the only thing that can is arenas, which are user-friendly only in Zig).
> We are using JDK25 and are considering rewriting parts of our product to Go because of lower memory pressure and faster startup time, i.e., cloud friendly.
Java probably will never have perfect warmup, but it's getting very good - https://openjdk.org/jeps/544 - probably in JDK 28.
As for memory, I think Java's memory strategy is generally misunderstood and I've given a talk about it: https://youtu.be/xr73mR7ii9M The footprint overhead exists to compensate for CPU utilisation when the CPU utilisation is more disruptive than memory usage. The problem is that many Java developers - and I'm not blaming them - don't understand this tradeoff and how to configure the JVM for optimal resource usage, but the great news is that a solution is coming soon, too - https://openjdk.org/jeps/8377305 - also possibly in JDK 28.
So it's very likely that both of these issues will be resolved six months from today, and you'd still get to enjoy better performance and telemetry than all alternatives.
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A couple data points, I like Java but I've seen metrics of container fleets at multiple companies that were memory constrained with low CPU usage sitting around underutilized. The reason in both cases was a bunch of memory-heavy yet CPU-efficient Java processes.
CPU utilization is a red herring. Unless you're doing heavy number crunching (which these days heavily favors GPUs) the practical bottleneck on CPU utilization for large general purpose programs (especially when spanning multiple cores) is memory bandwidth. And moving GC is terrible for memory bandwidth compared to both Go-style concurrent GC (which doesn't have to do bulk moves) and manual memory management.