Most importantly offline first approach. My notes are stored on a NextCloud share so many backups and notes are searchable with ripgrep when looking for stuff not interlinked or tagged.
Also roam research used to mess up quite often until they built client side caching. Still very annoying and frustrating to have to look at the dot turning green or staying brown. Could have improved but they should offer a complete offline solution IMHO, at least for editing markdown in 3rd party tools and re syncing.