I heard of the job through a recruiter, who at the time did not give me a good description of what the role was. The recruiters I worked with were more than nice, and accommodated my schedule. They even provided general background topics to brush up on.
The topics they provided were more along the lines of a software engineer rather than that of a DevOps candidate (implementation of hash tables, breadth-first search and common algorithms in Java, c++, etc...).
The interview process was not painful at all. The hiring manager I spoke with was a really nice guy and comfortable with causal conversation and idle chit-chat. He proposed a problem, explained it, and clarified any questions I had as I worked though the issue. After being done informed me how he'd approach the scenario given his chosen tool sets.