1. Introductory communication from the recruiter.

2. Coding test on HackerRank (fairly easy).

3. Four 45-minute interviews: a. Hiring manager (he did most of the talking). b. Design problem on a virtual whiteboard. The problem wasn't difficult: a system received 1K events/second, which needed to be fed to a black-box ML system once per hour, and certain actions needed to be taken based on its output. The interviewer was a bit antagonistic, which I wasn't expecting. c. Another coding test on HackerRank. This one was more domain-specific, but still not too difficult. I've forgotten the problem, but it required implementing sliding windows. d. A bar-raiser, who asked behavioral questions.

The behavioral questions were all pretty standard—nothing unanticipated.

I must add that Twilio was great during the whole process. They offered great communication, sent a good amount of information to prepare, and followed up quickly.