Cartes search and user experience was surprisingly good! Well done. I was caught off guard by having the requirement for a Bluesky account for reviews instead of something open source/federated but wasn't able to read the explanation page as it was french only, but I think the international version is still work in progress, so I'll gladly return in the future.

Initial attempts and results:

https://cartes.app/#8.61/37.5261/-121.7338 constant up and down movement at any middle zoom level, e.g. this one. zoomed far out or far in (<20km or so visible) it's stable, e.g. https://cartes.app/?allez=San+Francisco+Bay%7Cr9451753%7C-12... moves most of the screen up and down, while https://cartes.app/?allez=San+Francisco+Bay%7Cr9451753%7C-12... is stable. (this appears to be the case roughly anywhere, this is just an example) https://www.dropbox.com/scl/fi/orfhap34liecdon618wkv/Screenc... for a screen recording.

for below, all have "here" selected (not "everywhere") and this same view: https://cartes.app/#12.41/43.0435/-87.89962

"coffee": shows city names in other states, and two places in Iraq.

"valentine": shows... house icons? and a business icon in other states and countries. (top result is apparently a "commune" in France. not sure I'd use a house icon for that tbh)

"valentine coffee": good substring matches for the business name (3 results) and two results in other countries.

"val coffee" (exploring substring behavior): finds one good match from the previous search... but it also shows "Stone Creek Coffee"? what part of that node matches "val" but not "coffee" on its own? https://cartes.app/?allez=Stone+Creek+Coffee%7Cn5066972575%7... -> https://www.openstreetmap.org/node/5066972575

"vendetta": finds 3 good results, e.g. https://cartes.app/?allez=Vendetta+Coffee+Bar%7Cn11268671206... , but why does this work when "valentine" does not?

so... pretty normal results for open-source OSM apps afaict. maybe slightly better than average.