I got through two, hour-long phone interviews before I was turned down. They asked questions about distributed systems, my experience, and then moved onto programming questions. Then I could ask questions to them. Everyone was really nice through the whole process. The questions were fair.
1. phone interview
2. On site interview
The interview is quite difficult. SRE is new.
But SRE is very promising, so I will pick up more knowledge to prepare for another SRE interview.