I applied online. The process took 4 weeks. I interviewed at United Airlines in Feb 2018
Interview
First stage of interview was an online "on-demand" interview where you record yourself answering a given question. There were around four or five questions in total for the on-demand interview and you could re-record your answer as many times as you want. Took about one week to hear back with a request for a live video interview.
I applied through an employee referral. The process took 5 weeks. I interviewed at United Airlines (Chicago, IL) in Oct 2015
Interview
There was an early vetting process and then the scheduled interview. Make sure you have detailed responses to the situation based questions. Really consider a lot of process based questions and answers.