[ramchip]

Adding hardware doesn't improve single-request performance, so slow stacks can require a bunch of optimizing or caching work that wouldn't be needed on a faster one. At some point it also impacts productivity when the test suite is slow, the app takes a long time to restart, etc.

[CraigJPerry]

Sure it does, my home lab servers have a single thread performance approximately half that of a server today.

What’s the ping latency from US East to Europe? 80ms-ish? What’s a roundtrip to postgres with a regular business app type query, 20ms-ish? What’s the latency on a beefy rails app’s request handling, 40ms?

We’re talking 140ms best case for a slow stack. What can you get that down to with tuning work?

When your user comes along on their 4g connection with 800ms latency, will they be able to tell the difference?

Don’t get me wrong, I’d far rather invest time in making the stack efficient but from a business point of view, it might not make sense vs. just throwing hardware at the problem and spending your expensive engineering resources on making it possible to deliver more utility to customers.