The new feeds feature supports three different output formats.

Feeds in JSON format can be used for instance to compile a list of 'frontpage news' entries in a static cached file stored in your website bucket. You can then use client-side JavaScript functions to fetch and parse this file in order to render your latest news entries on the website. This will further improve performance instead of calling the lambda function repeatedly.

Other output formats include XML to generate a sitemap.xml, or Atom/RSS for news readers, as an alternative to the provided lambda functions which have to be scheduled using CloudWatch Events.

Check the feeds documentation for more information.