In GIS software development there is often a need to seamlessly integrate a simple or more complex GIS solutions into new or existing non-GIS applications. Depending on the non-GIS system, number of different integration technologies are used. From communication standpoint there is a client-side integration based on WebSocket technology, JS API or using more recent technologies like custom elements (e.g. Angular Elements). From complexity and functionality standpoint there is an option to use custom developed lightweight GIS or full featured GIS viewer/editor based on our own IGEO platform. This talk will share our experience and challenges we've ran into during the years of GIS development and integrations with other in-house or external systems.