That seems to only be for the Java code
How fast though is Java versus other languages? A show and tell page has submissions in Rust, C#, Go, Python, PostgreSQL, Python, C, C++, and more. These are hard to compare with one another since they have been run on different hardware, but there are some impressive results, including one under 5 seconds done with C on an AMD laptop, and a C# solution that runs in 5.3 seconds on a Core i5-12500 with 6 cores.
I just did a speedtest over wifi and got 530 down / 260 up with 45ms ping. I connected to a server a few states away and also got about the same with the closest server. I do have gigabit fiber though