Oh, that's interesting. ESA says they distribute the Sentinel data free of charge as far as I can tell. So I guess the issue is that you'd need to download and host the data yourself, rather than just do an API call to someone else's archive?

Anyway, it's a cool website, nice work!

Yeah and hosting it by yourself is slightly non-trivial as the storage requirements are in the PB range.

You’re exactly right. Sentinel Hub process a huge amount of data in real time, so it’s no small feat.