No, it's "if you already have engineers that know your stack and customers and business then getting rid of them to save a bit of short term cash is stupid unless you're out of runway because of bad business decisions." That is a tangential point to hiring more engineers. You may slow down the rate or hiring however the ROI for getting rid of them in a growing startup is silly imho. A collapsing startup is a different beast.

If a startup is laying off engineers then it’s dead in the water. That means it’s not growing and focused on cost cutting at the expense of velocity. Thats what a large company does. The issue isn’t AI but the startup fundamentally being broken and this being a last gasp for air before it dies.

There's exception and geniuses to every rule. In general however a simple solution will be much more difficult to argue a promotion around even if you make a ton of impact. You may get a top rating and a slightly larger bonus however not a promotion.

Every large company has a ladder for promotions that includes many words that basically come down to "complex." "Drive a year long initiative" or "multiple teams" or "large complex task with multiple components" are all examples I've seen.

This lets you not even need Python, r, Julia, etc but directly connect to your backend systems that are presumably in a fast language. If Python is in your call stack then you already don’t care about absolute performance.