I received an internal referral, followed by a phone interview. It included several knowledge-based questions and one coding question. After that, I was invited for an on-site interview.

I cannot reveal the actual questions, but broadly speaking, half of them were design questions, while the other half focused on algorithms and coding.

The algorithm questions were not overly difficult, but they required extremely fast completion (10-15 minutes each) and bug-free solutions.

Phone interview question:

Given a string pattern of 0s, 1s, and ?s (wildcards), generate all 0-1 strings that match this pattern.

e.g. 1?00?101 -> [10000101, 10001101, 11000101, 11001101].

You can generate the strings in any order that suits you.