The art is in knowing how to write software that doesn't perform like shit without doing all the work of measuring and refining. If you can save $100k in hardware costs in a couple days by just knowing what you're doing, that optimization is not premature.
And yet when Prof. Donald Knuth wrote that in 1974 paper[1] it was in this context:
> "The improvement in speed from Example 2 to Example 2a is only about 12%, and many people would pronounce that insignificant. The conventional wisdom shared by many of today's software engineers calls for ignoring efficiency in the small; but I believe this is simply an overreaction to the abuses they see being practiced by pennywise-and-pound-foolish programmers, who can't debug or maintain their "optimized" programs. In established engineering disciplines a 12% improvement, easily obtained, is never considered marginal"
also:
> "In the late 1960's we witnessed a "software crisis", which many people thought was paradoxical because programming was supposed to be so easy. As a result of the crisis, people are now beginning to renounce every feature of programming that can be considered guilty by
virtue of its association with difficulties. Not only go to statements are being questioned; we also hear complaints about floating-point calculations, global variables, semaphores, pointer variables, and even assignment statements. Soon we might be restricted to only a dozen or so programs that are sufficiently simple to be allowable"
In a recent comment I mentioned a youtube interview with Rico Mariani, a performance engineer from Microsoft, and he said that he often got called into projects approaching their deadlines and not meeting their performance goals.
In one anecdote he spent a couple of hours with a team and showed how their design could never meat the goal even with the fastest disks, CPUs, memory, and network. And commented how strange it is if they had spent a day at the start of the project whiteboarding out the design against hardware specs at the start of the project - and avoided months of wasted effort - that would be called "premature optimization".
> And commented how strange it is if they had spent a day at the start of the project whiteboarding out the design against hardware specs at the start of the project - and avoided months of wasted effort - that would be called "premature optimization".
Oof that hit hard. The last project I worked on suffered from a very similar disease, and it has really taken a toll on me psychologically. To work day in and day out on something that you can prove cannot work is unbelievably demoralizing. From an organizational standpoint, it makes a lot of sense to have an "internal consultant" who can deliver bad news like this. I tried to do it from the "inside" which was a huge mistake--got a negative performance review saying I had a "communication problem" because nobody wants to hear "negativity". I can come off online as kind of an asshole, so this may not seem credible, but I did actually deliver this news in a professional, measured manner. It's just that organizations are allergic to it, and their antibody response kicks in. You need someone who is not affected by the organizational hierarchy (or at least not that branch of the tree) to step in and deliver the bad news without fear of retaliation.
