I only got the call back for the video interview via modernhire, not the face to face interview, Although I didn't make it to CERN, it was a pretty good experience.
I applied online. The process took 2 months. I interviewed at CERN in Oct 2021
Interview
It was asynchronous. I had to answer to various question about how much I know about cern and my project. It was a little bit akward but not difficult. Therefore some people from specific team can call you for a more specific interview.