There are two separate tracks for SRE, SRE-SWE (same bar as SRE) and SRE-SE (Systems Engineering). While SE has a lower coding bar, it's arguably the harder of the two since they make up for it with Linux internals etc.
Other than that I was asked to implement a 'tail' command using my familiar language, and explain why deleting a file from disk doesn't free up the space.
Because System deletes only the “pointer” to the file and not the actual file. For the exact same reason, cut+paste is faster than copy+paste
https://www.lacie.com/support/kb/available-disk-space-does-n....
I did a bunch of those panels in my time. Imo if you read 2-3 books on unix/linux/networking and can complete this wargame in a couple evenings you’ll stand out quite a bit.
Kirk McKusick's "FreeBSD Kernel Internals" course[1] was recommended to me, and it was excellent. But not cheap at $1495.