Wall of text incoming: I just wrote some rough notes while I was reading this thread. It has been a while since I was in interviewing game but have been on both sides quite often. Feel free to ping me if you need any help or second opinions...

IC interviews:

For most platform engineer / SRE interviews, you will need benefit from coding practice. Questions are generally more grounded  compared to more complex algorithmic based questions for SWEs. Emphasis is more on your ability to write clean code, tests, demonstrate strong command on core data structures and commonly used algorithms and an eye towards defensive programming.

Few questions
1. Find top ten IPs from apache logs in the past one hour. 
2. Reverse a palindrome ignoring special characters…


For roles that are focussed on SWE, definitely go through leetcode. 


System design:
1. Be pretty comfortable with platform/infra basics like load-balancing, dns, kubernetes etc. How would you design a CI/CD system in GCP etc. 
2. System design by Alex-wu is a decent book, might not be super oriented towards platforms, but is very relevant for SRE type of roles.

Manager interviews:

Make sure you are prepared about the following few areas

1. References are king for manager interviews. Since management is a people game - having a strong reference can quell any minor issues.
2. Project  planning and delivery:  Give an example of a sizable project that you planned and executed on. What are the challenges, how did you gather requirements, worked with collaborators  etc.
3. People management. Examples of how you have dealt with low performers. How did you elevate your best performers. How did you keep morale of your team high. Make sure you can talk about these without revealing personal details etc. That will be a red-flag!
4. What got you into management? Have a thoughtful answer around your motivation.. Do you enjoy elevating people's careers.. do you find challenges around people + tech more interesting than dealing with just tech etc
5. System design interviews can be very important for junior-mid level positions. Go through the system design book for at least few things. 
6. Coding will be asked in jr-mid level roles, see above section for IC interviews - but generally you are given a bit more leeway for mistakes. 
7. Remember that management interviews can be very fickle, can range widely from people management questions heavy to tech heavy - especially at junior-mid levels.  Don't take it personally. 
8. Finally, you are interviewing the company as much as they are. Make sure you do groundwork in understanding what the company does, what are their core principles etc. Ask questions that will clarify your role.