Coding - string manipulation, list manipulation, file handling; see LeetCode company tagged problems but it mostly comes down to luck, i.e. have you seen this before? Behavioral - the usual "tell me about a time..." questions System Design - won't share too much here but check out some of the most popular Meta Research papers and conference presentations for ideas on what systems to study Operating Systems - a lot comes down to having years of Linux experience tbh, but check out Michael Kerrisk's "The Linux Programming Interface", Julia Evans' "Wizard Zines", and play around with a Linux distro for some starting points Systems Troubleshooting - Linux system administration knowledge helps a lot here. Use Fernando Duran's SadServers.com for some practice. Check out Brendan Gregg's content and know the "USE Method" and the "Linux Performance Analysis in 60000 Milliseconds" articles by heart.
Check out your Company Bowl for anonymous work chats.