Mechanical aspects... I grabbed Cracking the Coding Interview. I started doing online coding tests. I started studying modern C++. I was fortunate that I had a relatively easy, 40 hour day job at the time so the nights and weekends weren't too bad. It took a few months. I interviewed with Amazon and it opened my eyes to how much I didn't know(Also, I am so incredibly glad I didn't get that job). I kept studying. I kept interviewing. I tried to think of things I would be expected to know. As an older engineer with a lot of Linux driver experience I had to refresh my knowledge of the Linux kernel's various subsystems. It was a lot of work. It helped that I've been at this game a few decades though so it wasn't like this stuff was exactly new. The algorithm stuff was, but I'd done a fair amount of Linux stuff, C++(but C++ pre 11), lots of C and Python... I wish I could say I still remember a lot of what I learned.

As far as interviews go, I think I tend to interview pretty well when it comes to social skills. Problem solving is tough. I had to do a lot of whiteboard practicing. I probably over practiced this part because, in my experience, you're not really writing tons of code on the whiteboard. Yes, you need to write some, but it's typically short snippets or pseudocode.

I remember telling my interviewers that I didn't think I was a good fit for the job. It seemed more 'CS' than I could handle. I don't know why they went with me. I know the company was rapidly growing at the time so I probably just got lucky. Not what you want to hear, I know.