The process I went through took about a month only because I was employed at the time. It consisted of a phone screen, an in person meeting, a code challenge, a dev team meeting and a bunch of other meetings with senior management and other team members.

Interview with PM, then take home coding challenge, then review of coding challenge with dev team, the interview with upper management (only 2/4 showed), then an onsite showcase of the company. The whole process took about 2 months.