They reached out to me via LinkedIn, I was screened by a phone interview and immediately they suggested a time and date for the interview.
Essentially, the interview questions were all about my current employer back then as my employer was their main competitor! Actually, it was a kind of muscle-flexing because they went to an extent of literally saying something like "we are much better than your company because we have x, y & z while your company doesn't have any!"
I later on came to conclusion that the purpose of this interview to know some "intel" about their main competitor.