Recommendation for number of workers: cores × 2?

Installation
16

BTW here is what Falco was looking at to make that recommendation:

The image is a line graph showing active web requests over time with spikes at 22:45 and 00:00, and queued requests being highlighted with a red arrow. (Captioned by AI)
The image is a line graph showing active web requests over time with spikes at 22:45 and 00:00, and queued requests being highlighted with a red arrow. (Captioned by AI)1124×337 69.3 KB

I’d bump 8 → 12. Gives you some headroom and should clear out those queues.

That large spike, BTW, is indicative of the other requests waiting on… something, probably a common lock. Perhaps a megatopic post.

If you can get postgres usage metrics as well, that would be useful.

megatopics are a weak spot, see Improving Instance Performance (Megatopics, Database Size and Extreme Load)

Consider breaking these up or using chat instead (I see your largest one with 8.9k replies is explicitly a chat room).