My big issue with the M1 generation is the lack of more E-cores, which get assigned a lot of the OS background tasks. When working at the top of the RAM limit, I'd notice issues around lag to the point that I started looking at CPU stats and found those two measly e-cores completely maxed out for hours on end. Occasionally a crash, though that could be RAM related rather than CPU.

A bit of googling around seems to point that architecture as somewhat of a problem for others, and might be why Apple quickly moved to put more e-cores on the later generations.

Something to consider. Never managed to get proper distinct confirmation that this was the problem, but a (corporate) laptop upgrade did get me out of this pickle.

I don't think you're doing anything wrong. I struggle with similar workloads on 32GB RAM. Compute isn't the issue, once I have a JetBrains IDE open, a dev environment, some browser tabs, Claude, and a bunch of other crap Electron apps I need the machine is already swapping quite a bit.

Years ago there were frequent crashes (kernel panics) i could directly relate to IntelliJ (PHPStorm, etc), so it might sound dull but upgrading to the latest versions is the first thing I’d check. In this case even a manual check on their website instead of relying on the auto updater to work.

I have found that my M5pro gets unstable when I really stress it's memory use. I think that with 8 or 16GB you are going to hit this quite a lot more than I do with 48GB.