One of our company clients needed to dynamically fetch the RSS feed news from popular Latvian news site and create them as posts in their page.
As full content was not passed through the RSS feed, the news block just needed to redirect user to the news site address.
As RSS feed is updated frequently, I needed to come up with solution to save server processing power and keep the good page performance.
So I decided to create a custom RSS Feed importer plugin that fetches the posts, update the post meta with links, thumbnails and all needed info.
Using transients I made the plugin cleanup system when the plugin is enabled or disabled it deletes all the posts and categories.
The plugin updates posts on 20 minute cronjob schedule.
Major thing to remember building things like this plugin is to make sure to run methods in correct sequence in order to optimize the requests that needs to be called on DB and other resources.