So here I'm thinking I must be doing something wrong because I can't figure out how to make this UI dingus I'm working on do what it needs to do without generating two AJAX requests rather than one, then for the sake of comparison I load up an allegedly best-in-class enterprise CRM to see how it's handled there, and discover that an equivalent operation somehow manages to hit the server seventy(!) separate times, and you know what? I think I might actually be on the right track.
This is a screencap of the trace telemetry from DataDog of a single POST made to an API I was troubleshooting last year. No one had ever gotten this notification before and our DataDog rep actually whistled when he saw it. The final trace chart was 288MB of minified .js.
That's 288MB of text.
What that js was building was a representation of the traffic that this single POST kicked off, all the way down to the final DB call. I'd show it here because it was a truly unhinged chart, but it shows privileged information. As a result of this single POST, forty four thousand, four hundred and sixty two processes were called.
From a single POST.
This was a log-in call.
The team I was embedded with didn't understand why their enterprise-grade application was non-performant.
All this is to say that frequently all "enterprise" means is "people were paid too much to make this."