It's not that complicated, it's just not something engineers are usually used to do. If you use an AWS service, you look at its pricing.
Take s3 for example: whenever you use it, you'll pay for outgoing bandwidth, PUTs, GETs, and storage.
So you seek to minimize all of these:
1. Bandwidth: use cache layers. This also minimizes GETs.
2. PUTs: design your app in a way that doesn't do unnecessary inserts into s3. Consider alternatives such as redis, postgres or filesystem depending on the need.
3. Storage: compress your objects if they compress well. If they aren't often accessed, use storage classes and auto lifecycle management.
Pricing in AWS generally reflects some kind of engineering limitations you will face at scale in the first place, so it makes sense to go through this whole exercise either way.
I wish programmers had the prestige it deserved for combining Science, tradition, authority, and art.
Engineers are not allowed to use tradition, authority or art. They are restricted to being modern day calculators.
Nothing is wrong with either.
An interesting analogue would be the Automotive industry; As time progressed, Companies focused more and more on 'engineering' versus art/tradition/etc. But as the industry evolved, "Flashy" vehicles that took risks became moreso either a halo product for a brand, or relegated to Luxury/Boutique.
And, of course, there was the dark side of this shift; A good example from the 70s, the level of 'engineering' driving the design of the vehicle and it's assembly didn't take into consideration the actual line worker; in Ohio the workers wound up getting overworked, burned out, and in some cases actively sabotaged the product, because they were being treated like automated machines.
Engineers are applied scientists.
Programmers are not applied scientists.
I'm guessing you are neither?
Software engineering could learn a lot from, say, civil engineering. It could also learn a lot from interface design and I'm sure even microbiologists and astronauts could teach us a lot. Engineering is not special.