Hi,
In our map-based application, currently we are using ArcGIS API for JavaScript version-4.x along with Angular 2.
Also, we have an ArcGIS Server (Version 10.x) on which MAP REST APIs are hosted. The application fetches data from these Map REST APIs.
The problem that we are facing is, when we fetch the information from the ArcGIS server for GLOBAL Base Layer, US State Layer and US County Layer - the response payload size is in MBs, so it's taking lot of time to render the layers.
e.g. for the US State Layer - Response Payload is around 11.40 MB and it takes around 15-20 seconds to render the layer.