Social media apps are perfect candidates for using graph databases and GraphQL APIs. The combinations of complex data queries and relationships are endless.
Take Reddit for example. The app consists of “subreddits”, or topics. Users can create posts in these subreddits, which means that there is a many-to-one relationship between posts and subreddits. Each post belongs to exactly one subreddit, and each subreddit can contain many posts. Users can comment on posts, leading to another many-to-one relationship between posts and comments. Each comment belongs to exactly one post, and each post can have many comments. There is also a many-to-one relationship between users and posts and between users and comments. Each comment and post is made by a single user, and a single user can have many comments and posts.