PostGIS can write to GeoJSON so you can have a simple flask or bottlepy webserver to query the db. Then use leaflet GeoJSON layer to pull down the data and render it on map.
There is of course the newer vector tiles which is a better solution in many situations but a bit more complicated to get going. Crunchy Data have made some good examples and a nice tile server for this.
There is of course the newer vector tiles which is a better solution in many situations but a bit more complicated to get going. Crunchy Data have made some good examples and a nice tile server for this.