I met them first at our career fair. There were one round of behavior on test and a technical phone interview before this event called "super Saturday".
They would pay for all expense for the trip to they NYC headquarter. The super Saturday includes a series of interview through out the day. 1, a written test on paper for basic software engineering topics, it's not hard but comprehensive. a on-computer test mainly for html, css, and javascript, the main content is to replicate the demos by using css, html, javascript.
2, talking to empolyees, introduction of teams' job. (seems not interviewing)
3, behavior interview by two employees. not HR people but employees.