I applied online. The process took 2 weeks. I interviewed at HarperCollins (New York, NY) in Jan 2018
Interview
Phone screen lasted only 5 minutes (presuming the HR person was busy) and seemed more interested in asking if I had any days free. Told me she'd send my resume to her manager and she'd tell me if there was a response. Never heard a word back.
Interview questions [1]
Question 1
Why are you interested in publishing Children's and YA books?