We have also had some users build some fairly large Pynecone apps including our whole website built in our own framework.
Aside: I get grouchy about the term "low-code", mostly because it's almost always a lie (you're going to need the code, and most "low-code" systems just hide how much that's going to hurt - which is why we put the code front and centre), and it causes people to lump Anvil in with, eg, Retool rather than, eg, Pynecone/Viola/Beeware...but this is definitely getting off topic ;)
Interested to hear how your scale-up/B2C users deal with the round-trip delays - I guess that's less of a deal with websites than interactive apps? (Should probably have grabbed you at PyCon to ask, but we were both pinned down pretty hard! I did manage to wave at you though, I think...)
Will be improved in the future as we start to offload client side actions with wasm, starting to do this but the python wasm ecosystem is still maturing
I didn't know about either Pynecone or Anvil, and have a side project for a friend that might be well suited to one/both. So I'm both more enlightened on options, and more predisposed to both given the positive dialogue here. Thanks for both.