I hope you find this article as a reference from some work I have done with WFS-T and Geoserver. I don’t really use Geoserver or WFS anymore while we build XYZ, the open source spatial data and application interface at GEOLYTIX.
The implementation of dynamic vector tiles is discussed in a previous medium post. Earlier article highlights the creation and caching of tiles in PostGIS.
This article focuses on the drawing and editing of geometries through an OpenLayers map interface. The complete example which uses REST endpoints provided by the geolytix.xyz/dev instance can be found in following fiddle.