[userundefined]

Yep, there are a few guidelines I've found on the web that would be good to cross-reference and these are good pointers, I'll look for ways to do so while trying to keep things relatively clean (I'm a backend guy so UX is always an adventure). A couple of pointers for construction I did come across are: - https://communicrossings.com/constructing-crosswords-grid - https://www.nytimes.com/article/submit-crossword-puzzles-the... (from NYT themselves).

> I’m guessing there are some rules about symmetry and no two-letter words that you can help users with.

Yes, and figuring out how to do the validation in a sensible way is probably my next step. I already have the encoding figured out, in fact if you examine the HTML you can see the grids as b64 binary strings, so the next step is the UX.

> Auto filling on an empty grid basically does all the work except clue writing

Sort of, having looked at a few other places that do this type of thing seriously there are other things about construction I'm not doing yet, like avoiding "CAT" and "CATS" or other substrings in general, and scoring words. I support the latter, but not on my poor E2 GCE instance (need more RAM). Clues aren't a problem I'm ready to solve yet, so I just cross-ref a nice site that has some of the historical ideas.

> I noticed the page hang when submitting that.

Yep, getting hugged to death :)