If we want to host with anything more we should make sure that exercises are deleted after some time (even if the only personenbezogenen Daten that we collect are the names that users give themselves). Since we now have a full export/import feature, my opinion is that we do not need to consider people keeping exercises online during preparation or such, and that we can simply auto-delete exercises that are untouched for say 30 days.

Are there any other options?

See previous discussion in #183 and related notice at the end of backend/README.md.