I was contacted by a recruiter. After that, a phone interview lasting about an hour, with an easy task and some Big O notation-related questions. It was followed by an on-site interview for about 4 hours.

First two rounds were technical, and the following ones were more conversational.

1st round was easy, took about 20 minutes, and the rest was around that question, and me asking the interviewer some questions.

2nd round was an OO design question. It went okay. I asked several questions before diving in, thinking it would help, but didn't get right answers for some cases, which I haven't mentioned to the interviewer (i.e., an answer that made me think differently during the solution).

Other two rounds were about what I did, what I am doing, and what I like to do. Technologies I use, the type of business I am in, etc.

Everything seemed very okay, which led me to think I would get an offer. But I got no offer, and the reason was I am not proper for the senior level they were looking for. I think questions were low enough to decide if a person qualifies as senior or not.

Whole case took around 2 weeks.

Basic algorithms & data structures questions related to their product.

OOD whiteboard question.