Applied online, then had the standard 1/2 hour screen phone call, which went well. I was given a take-home project to write which was a full-stack application. That seemed a little odd, but the directions said if you were applying for a back-end job, don't focus on the front end, focus most of your energy on the back end, specifically related to performance. After I finished the app I submitted it and then had an interview several days later with someone from the company, which is where the problems started.
He started out by going over the JavaScript (front-end) code, line by line. I figured, well, we'll get to the main, relevant code soon, but after a half hour we were still looking at the front end code. When we did finally get to the back end, he only wanted to talk about basic questions about how the API worked - how data and errors got passed back to the client. His questions seemed extremely strange at times. The basic structure of a web API is pretty straightforward, so I'm not sure what we were proving, other than I know how to write one.
When we finally got through that, I asked if we could look at the back-end code that was related to performance and searching, and he said he wasn't interested. That seemed pretty odd, since that was (theoretically) the whole point of the job, and the sample app.
After going through that exercise, he said that everyone knew that the word "Senior" in a job title didn't really mean anything, and then he asked if I was a real Senior Developer. When I said, yes, my resume is accurate and I have been in senior roles for a number of years, he asked whether that just involved simple programming, or whether I'd done any technical architecture work. And so on, all with a fairly demeaning attitude.
I've worked with people in the past that were arrogant, abrasive and clueless all at the same time, and it wasn't any fun. For me, life is too short to do that again, even with cool technical problems and the ability to work remote.