Most developers work at banks, insurance companies and other “enterprise” jobs. Even most developers at BigTech and who are working “at scale” are building on top of scalable infrastructure and aren’t worrying about reversing a btree on a whiteboard.
Agree that the whiteboard thing is often not applicable but it's so nice when a developer has efficient code if only because it indicates that they know what's going on and also that there are fewer bugs and other bottlenecks in the system.
Those bugs don’t come from using the wrong algorithm, they come from not understanding the business case of what you’re writing. Most performance issues in the real world for most cases don’t have anything to do with the code. It’s networking, databases, etc.
Your login isn’t slow because the developer couldn’t do leetcode
No, it's because 50k reads of settings are happening with a SQL Table in memory that's queried via SQL statement instead of a key/value hashtable. (real world experience, I think it was close to 28k reads, but the point stands)
