Azure Data Explorer has supported geospatial functions since 2019.
Now KQL has been extended with the geo_polygon_to_s2cells function. It takes a polygon or multiPolygon and a S2 cell level as input and creates an array of all token strings which cover it.
The query pattern of geospatial joins is oftentimes used in various mobility solutions (geospatial telemetry and static reference data), geospatial risk analysis and agriculture optimization using weather data. It consists of a coarse-grained join using the S2 cell coverage provided by geo_polygon_to_s2cells and the later exact validation using the geo_point_in_polygon function.
Please find more details on this blog post.