[mgkimsal]

On top of that, I've never interviewed at a company doing that level of complexity where I was going to be expected to write it, from scratch. By the time they're interviewing people, they have something in place, and even if I actually could write it better, politics and personalities are likely going to prevent that anyway (or perhaps even legal).

More than likely you'll be working on a team, where you need to understand some of these concepts, and you'll grow in to them. Almost every single person on that team did not come in off the street with expert knowledge in those domains.