I helped some hotshot developer (who is clearly better Python programmer) debug an app which serves vector tiles. He insisted he wants to use MongoDB, because "

I helped some hotshot developer (who is clearly better Python programmer) debug an app which serves vector tiles. He insisted he wants to use MongoDB, because "he doesn't need to learn SQL". The app worked mostly fine except for low zoom levels in which some country outlines got chopped. The issue was that MongoDB only has spherical geometry as a first-class citizen. If you make a query against a 4-vertex bounding box, then on low zoom there's a discrepancy between querying on a sphere vs querying on WGS84 or Mercator. The solution was to densify vertices of the square against which objects to be served were intersected.