They contacted me via email. There was an HR call explaining the process, then another call to get me ready for the interview. One online coding round and one system design, followed by a hiring manager interview.
I did not like the process because of two reasons:
1. The HR calls I had were so unprofessional, I mean on a different level unprofessional. Didn't expect this from booking. The guy either woke up 5 minutes before the call or slept right after, don't know which, but used the excuse of bad internet connection for the voice and not turning on camera. Unpleasant discussions there.
2. Talking to the HR, I made sure PHP is in the list of the languages for the HackerRank problem I'm supposed to solve on the coding round. Also mentioned the fact that sometimes this is not the case, that's why I'm asking and wanna make sure about this, so that if it's not I can use my time to practice with a different language. They assured me that I can use PHP. Fast forward to the interview, boom, no PHP option. Lost my focus since most of the time I was trying to remember how to do something in Python. However they offered me to write pseudocode, still, I didn't feel fine and was surprised and lost myself there.