Many people use external sites like IMDB, TMDB, Trakt, Letterboxd, Rotten Tomatoes, etc. to rate movies and keep track of which ones they’ve watched. It would be nice to be able to sync these ratings and watched state with Plex, similarly to what the Trakt plugin for Kodi does: https://kodi.wiki/view/Add-on:Trakt
The function could be incorporated in several ways. Either through syncing accounts through APIs, or even just by manually exporting and importing .csv.
PS: I found some other topics with sorta similar ideas, but those were either locked or not able to vote on.
Here are the ones you can already vote on. Those are discussing specific integrations to sync ratings etc. with one platform
There’s also the one-size/site-fits-all suggestion asking for an extensive Trakt integration.
I suggest you comment/vote in those threads (or just the ones applicable to your use case) in order to help us avoid distracting or cannibalizing votes (closing this one as a duplicate).