O'Reilly logo
  • Derek Harmon thinks this is interesting:

see the search results immediately

From

Cover of Microservices for the Enterprise: Designing, Developing, and Deploying

Note

At least, the user wants to see the beginning of the search results immediately. Other search results can continue to arrive while the relatively-slow human examines the first screen of search results.

This sounds asynchronous, meaning the authors were wrong to use it as an example where synchronous communication is mandatory.