It's funny how beginner programmers think you can step into the industry and coast by on using established algorithms, thinking they will never need expert knowledge themselves.

A few years into the industry and I have realized that when it comes to highly customized requirements and you need to write and test complex algorithms yourself, that's when you better have your expert knowledge backing you up because aside from A.I. assistance, nothing is going to help you.

Oh, how complex it can get. I've had to think about rethinking entire architectures that gave me weeks of real headache, algorithms that required the deepest fine-tuning, tree traversion, generics, interfaces, extension methods, factory, singleton, decorator, facade, etc.

In short, you better know your way around the language you are programming in. You also need to know your algorithms and optimizations because when things are black box to you, that's not a good feeling.. especially not when people are relying on your expertise. The real world is complex and thus we model its complex models.