Contacted by the recruiter for a phone screen and was scheduled for a day-long onsite interview.

Basic questions on the resume and networking protocols and how they work at different layers.

One of the interviewers was rude and started bragging about himself, stating he had 10 years of experience and that we were "nothing" to them.

Prepare well on data structures and algorithms.

Have good knowledge of the TCP/IP stack.

Know how HTTP and HTTPS work.

I already had an offer from another company, so I didn't feel like working with them because of that particular person.

Protocols and DS (linked lists, Stacks & queues)