I'm the manager for the infrastructure team at Outreach. I'm happy to speak to this & follow up to answer any questions.

We have a bit of a phased process where our recruiters have a phone call to do a basic screen. Then we have a phone tech screen focused a bit more on general programming.

The onsite loop has a 2 hour pairing session, an hour long session focused (lightly) on distributed systems, and an hour long coding session focused generally on algorithms (done on a whiteboard, laptop, or wherever you feel comfortable), then a session focused on our company values.