GeoMapFish is an open source platform for the development of web-based geographic information systems (WebGIS). The platform is rich in functionality, highly customizable and offers multiple interfaces - desktop, mobile, administration and an API for integrating maps into third-party applications. OpenLayers and an OGC architecture allow the use of different cartographic engines: MapServer, QGIS Server, GeoServer. A solid and proven backend enables opening up to other web viewers. The platform has been developed in close collaboration with a large user group. It targets a variety of uses in public administrations and private groups, including data publication, geomarketing and facility management. A highly integrated platform, a large number of features, fine grained security and a mature reporting engine are characteristics of the GeoMapFish solution. In this talk, we will present the key usages, the state of the migration process to web components and latest functional developments. We will share our experiences from the productive operation of GeoMapFish-based geoportals in various Kubernetes clusters.