I applied online. I interviewed at Sierra Nevada Corporation
Interview
First there was the application, then a few emails, then one phone call (which was as far as I made it) with one person from the team. It was a pretty quick turnaround too.
Introductory screening, phone interview, then virtual video interview with the team you would intern for. Interviews were fairly informal, but researching what the team you'd be working with does and how you would fit in is very valuable.