Status: Backend Engineer, Non US school
Position: Senior Software Engineer at a Tier-1 Company.
Location: Silicon Valley

Interview Process:

1. Telephonic interview: Expected to solve 2 Medium-Hard questions.
2. Virtual Interview:

• 1 System Design Question: Create an easy backend system for small scale, non distributed system with followup question on scalability, reliability.
• 1 Behavioral: Shared work experiences and project detail. Few questions like conflict, mentoring, how to ramp in a new company, what you are looking for, what motivates you. Additionally, one easy coding question in 10 min
• 3 coding questions: 2 questions each. A lot of tree questions, array questions, Trie. They did not expect DP solutions. Time and complexity necessary with each. I saved time for asking questions in each round by completing coding early.

How I prepared:

1. Passively started practising after Covid hit. LeetCode, Cormen and you tube algo videos for first 5 months. 500 Problems in Jan-May.
2. Gave lot of mock interviews in π_rªmπ. But it wasn't very useful after 20 interviews. 10 System Design and some coding. Coding ones felt like waste of time.
3. Bored of coding, focused only on system Design from Jun. Read books, research papers. They were useful in current Job too, so it was more than job preparation. June-Aug. Also taught system design to my friends in valley, took mock interviews with them.
4. Interviewed at tier-2 companies and declined those offers in July-August.
5. Failed a behavioral interview for a Principle job, so focused on Behavioral by reading management books in September-Oct.
6. Even interviewed for Management role for Practise(for a tier-1 non-IPO company) and did better than expected, but I was rejected at the end due to no experience of direct management.

I was more than well prepared for all kinds of interviews. I didn't get nervous because I had interviewed with more than ten companies and done enough mock interviews.

NOTE: Communication is critical in every company's interview. Stay Humble but proud of your work. Do not try to explain your work which is over-technical in behavioral, and if you do, give them a heads up.

While preparing, I also over-achieved in my work at a Tier-1 company by moving very fast.
I didn't really expect to get a good offer this year (Covid Year), so I wasn't stressed at all.
Also have other competing offers. Haven't decided yet.

Edit:
Resources for System Design-

Books: Data intensive applications(Read it twice). o'reilly Kafka definitive guide, Zookeeper.
Websites: Infoq.com,highscalability.com/all-time-favorites, You tube videos

Papers List:
(Might be too exhaustive and most of them is not needed for Fb E5 at all. They might be useful at work and E6 interviews)
AllAboutMemory.pdf
amazon-dynamo.pdf
endtoendArgument_SystemDesign.pdf
Espresso.pdf
facebook-cassandra.pdf
facebook-haystack.pdf
facebook-tao.pdf
google-bigtable.pdf
google-gfs.pdf
google-mapreduce.pdf
google-pregel.pdf
google-spanner.pdf
ibm-garbagecollection.pdf
K-VStore.pdf
linkedin-kafka.pdf
memcache_scaling.pdf
Replication&Dangers.pdf
Resilient Distributed Datasets.pdf
TwitterHeron.pdf
yahoo-hdfs.pdf
yahoo-zookeeper.pdf

Can't stress this enough: Prepare for System Design of a Scheduler. In all interviews I found this useful. I worked on such a project and you can look up how your companies does this.