Arch and its derivatives look like the trend

It's because nobody writes "I use Debian BTW".

Debian.

Your family will hate you if you'll change their distro and DE every time you visit them. Distro hopping is normal for the first couple of years, but do it on your own machine.

You may install BOINC and contribute to scientific computations.

no functional programming languages like Rust

What?

Don't search tasks for a tool. Search a tool for your tasks.

Jenkins is not a modern CI. It is a historical milestone, but if you read an article you should see that it was replaced by other tools. Now I don't recommend considering Jenkins for new projects. It it fast to set up but extremely hard to support and full of old bugs and legacy code. Writing Groovy pipelines is much harder than pipelines in gitlab/github/forgejo/etc. Tens of plugins you have to use even for simple tasks have inconsistent syntax, many of them are buggy, they often become unsupported or deprecated. This all consumes lot of resourses: I maintain an instance that eats ~4G of RAM being idle.

Premature optimization is the root of all evil. Implement algorithm the easiest way possible, profile your application, determine if this implementation a bottleneck or no. If yes, try other implementations, benchmark them and find the fastest one. Note that optimized go code can be faster than non-optimal code in rust, C, assembly or any other language.

Any distro you are comfortable with.

You don't have to clean your ~/.cache every now and then. You have to figure out which program eats so much space there, ensure that it is not misconfigured and file a bugreport.

I totally disagree. Git is not hard. The way people learn git is hard. Most developers learn a couple of commands and believe they know git, but they don't. Most teachers teach to use those commands and some more advanced commands, but this does not help to understand git. Learning commands sucks. It is like a cargo cult: you just do something similar to what others do and expect the same result, but you don't understand how it works and why sometimes it does not do what you expect.

To understand git, you don't need to learn commands. Commands are simple and you can always consult a man page to know how to do something if you understand how it should work. You only need to learn core concepts first, but nobody does. The reference git book is "Pro Git" and it perfectly explains how git works, but you need to start reading from the last chapter, 10 Git Internals. The concepts described there are very simple, but nobody starts learning git with them, almost nobody teaches them in the beginning of classes. That's why git seems so hard.

I usually use something like du -sh * | sort -hr | less, so you don't need to install anything on your machine.