Google recently put in beta Google Cloud SQL for PostgreSQL which targets PostgreSQL 9.6 and seems like they plan to stay in line with PostgreSQL offerings similar to the Amazon PostgreSQL RDS and Aurora offerings. I was curious to see what kind of extensions they support.
In Google cloud blog article Cloud SQL for PostgreSQL for your mobile and Geospatial applications in Google Cloud PostGIS is explicitly mentioned as supported. Presumably because Descartes is one of their case studies which I can only guess probably uses PostGIS based on the quote from Tim Kelton, Descartes co-founder:
"Our individual teams, who are building micro services, can quickly provision a database on Cloud SQL. They don't need to bother compiling Geos, Proj4, GDAL, and Lib2xml to leverage PostGIS. And when PostGIS isn’t needed, our teams use PostgreSQL without extensions or MySQL, also supported by Cloud SQL."
Excerpted from their article:
Geospatial support: Easily enable the popular PostGIS extension for geospatial objects in Postgres.
It's unclear from the article what other extensions they support though. Maybe I'll have to try it.