You made an optimization for the future when enough bottlenecks have been fixed such that this one part becomes the bottleneck.
In other words, all engineering is time- and cost-constrained. Anybody can build a good chair for $10,000 or a good PC for $100,000. Doesn't mean it's good engineering.
BE LOGICAL! Of course you first fix the big bottlenecks.
>good PC for $100,000. Doesn't mean it's good engineering.
Of course it is...or can you gold platter a pc case?
And some people can build a great PC for $1,000 that runs circles around the good PC for $100,000.
There's so much more to engineering than thinking in terms of time and cost constraints. Those are real constraints, but they're not the most important.
Engineering is design. If you have good design, good insight, you can do things that people with infinite time and budget could never dream to achieve. You can start making a product that's a hundred times more powerful for a tenth of the price in a fraction of the time. If you don't have good design, good insight, then no amount of time or budget can help you.
1. Adding the optimization didn’t make the code more complicated.
2. Adding the optimization didn’t introduce a bug.
3. This part of the code will be a bottleneck in the future. The time spent optimizing is a write-off if the project is canceled or that portion is replaced.