How do you rate stuff you view and get recommendations
I have jellyfin with the radarr/sonarr/prowlarr combo going. I can "heart" things in jellyfin. But it's recommendations are only things I already have downloaded. I see discovery in radarr, but no way to tell it if the movies I downloaded were good or bad. So I must be missing something.
You can use jellyseerr. I have been using a lot the "coming movies/series " section, once installed. AFAIK, doesn't have it's own algorithm, and relies on tmdb trends. But it can be integrated with *arrs , so usually I prefer to spent there 5 minutes and made all my requests to sonarr and radarr. Also, has docker implementation, if it can be useful for you.
I use Trakt for tv and movies and ListenBrainz for music. Both have plugins to allow them to integrate with Jellyfin.
Never used Trakt, but I'm a big fan of ListenBrainz. It's a large part of why I felt able to cancel my Spotify subscription
Overseerr
Specifically, since OP is using Jellyfin, use a fork called Jellyseerr
If you would like to keep track of the movies you watch and give them a rating from 1 - 10, I'll suggest Movary. I'm a contributor of the project and the goal is to eventually add support for TV Shows as well.
Recommendations for movies and series are overrated because most of the stuff out there is bad and if it’s not is probably on some recommendation list all over the web
With music is not so easy but for books/movies/series I have no issues
Jellyseerr?
Movie scrobbler, i.e. trakt, letterbox, etc.
Outside of self-hosted solutions, there's JustWatch, which allows you to create an account, add movies and TV shows, and then you can rate them and get recommendations for it. It's not FOSS, and you do have to create an account, but it does let you have a universal watch list for all services you own, and then see what people are watching and get recommendations.