The REST API is one of the three major focuses that Matt Mullenweg announced for this year. On the other hand, Multisite has always been a minor focus on the WordPress project, as the number of its users is relatively low. However, those few who maintain larger WordPress setups usually activate Multisite and need its functionality as much as ever.
With WordPress 4.7, the REST API content endpoints were merged into core – however without any proper handling of Multisite. The Multisite team has stepped forward and announced getting the REST API compatible as their primary goal for 2017.
In his session, Felix will talk about the efforts of bringing Multisite endpoints to the REST API and the challenges that arise as a result.