I remember I got at least one phone screen and three or four onsite interviews. All of the technical interviews were about OS details since I applied for a Linux kernel job.
OS details
The following metrics were computed from 36 interview experiences for the Red Hat Software Engineer role in United States.
Red Hat's interview process for their Software Engineer roles in the United States is fairly selective, failing a large portion of engineers who go through it.
Candidates reported having very good feelings for Red Hat's Software Engineer interview process in United States.