Search aggregator for multiple clothing retailers. Just search for a term like 'White shirt' and see the results of many major retailers in a single page.
You can algo sort and filter the results by many options, such as: prices, discount, etc.
Results are sorted by default based on user interactions, so we keep a feed of "hot" articles.
Schema registry as a service. Ever needed to exchange serialized messages between services that can't access a common schema registry? Say no more.