And if you know in advance that a function will be in the critical path, and it needs to perform some operation on N items, and N will be large, it’s not premature to consider the speed of that loop.

We will optimize it later, we don't have time for that right now, it seems it works fast enough for our needs right now.

"Later" never comes and all critical performance issues are either ignored, hot-patched externally with caches of various quality or just with more expensive hardware.

Plenty of people seem to understand it as, "don't even think about performance until someone has made a strong enough business case that the performance is sufficiently bad as to impact profits".

IDK if it can be applied in all situations.

Sometimes, especially when it comes to distributed systems, going from working solution to fast working solution requires full blown up redesign from scratch.

well you see, in corporate (atleast in big tech), this is usually used as a justification to merge inefficient code (we will optimize it later). That later never comes, either the developers/management moves on or the work item never gets prioritized. That is until the bad software either causes outages or customer churn. Then it is fixed and shown as high impact in your next promo packet.

I agree with you. "Premature" is the keyword. Bloated software is the result of not having the intention to optimize it at all.

> Make it work first, THEN make it work fast

1. I have seen too many "make it work first" that ended up absolute shitshow that was notoriously difficult to do anything with. You can build the software right the first time

2. The "fast" part is what I think too many people are focusing on and in my experience the "THEN" part is always missing resources utilization and other types of inefficiency that are not necessarily related to speed. I have seen absolute messes of software that work really fast

Ditto here