I worked at YouTube full-time (More than a year)
The most diverse place I've ever worked at and everyone got along beautifully. I hand that to good management.
The only person I had a personality conflict with was my immediate boss.
Advice to Management
Notice when your people in charge bully their employees
I applied through an employee referral. The process took 4 weeks. I interviewed at YouTube (San Bruno, CA) in May 2017.
It is a 3-stage process, starting from a Google Hangout video interview, followed by an onsite interview day of 3 interviews with different focuses on technical skills, technical case study and business case study. If the onsite goes well, you'll be scheduled a call with the director for the final call.