I applied through an employee referral. The process took 1+ week. I interviewed at Charter School Services (Philadelphia, PA) in Jan 2016
Interview
you send your resume, and if you meet the requirements they can call you in as early as the next day. The interview took place in a group setting of about 5 people. They go over rules and expectations. Ask you questions in a group setting then a few questions one-on-one between you and the interviewer. It was fairly easy.