Recently I interviewed with Discovery, although not for any of these exact 3 positions.
Had an HR screen, timed online programming test, then a phone call with the hiring manager -- who then ghosted me. He seemed obsessed with MongoDB migrations and upset I hadn't done any.
I realize it prob wasn't you and it's up the hiring manager but ghosting is unprofessional, IMHO. If I'm going to take time to pass a technical test and have 2 hour-long phone call interviews, at least e-mail me later to say no thanks.