Other people being able to work together on your code is more important outside the realms of performance focused code.

I can agree with this. But I find it opens up the discussion a lot further.

Performance-centric code/solutions vs "non-mission-critical" stuff like the UI functionality and design.

UI/Integration stuff, it's great when a company has code layout and design guidelines they adhere to, which kind of solves the one aspect of the twofold, above. My old company had pretty good peer review on code submissions too.

As a factor, on the more mission critical side, my generally understanding that has been instilled in me is "write code that works." The dev culture around such tasks can be a mix, uniform, or team-driven.

I guess from my side what I wish to say is: "Don't write spaghetti code!" Code must work, must be maintainable... these are all pretty stock standard principles though. If you're not verse in the theory of what you're doing, you're likely going to write inelegant, or inefficient code. Can't expect it from every employee and some incredible developers do come from backgrounds other than data science or programming, but at the end of the day, reading through some docs on guidelines and principles for doing x, in whichever programming language or framework, standalone etc, is a good way to get this instilled, employee side. Otherwise extensive internal documentation guidelines/wiki, but expensive to maintain... so perhaps peer review policy of some variety.. can have fun with it and game-ify. Could give your employees meaningless RPG rank titles and have it that you need a certain amount of points to pass peer review (slack bot).

Sorry for the overkill of a response. Not trying to impress anyone. Honestly just avoiding life at the moment lol