D3.js is a powerful tool for visualizations. Some people get confused because they think is a Chart Library, but to be honest , this is quite unfair. D3.js brings you the power to link DOM elements with data and make them interactive.
People you should know
D3's creator : Mike Bostock
Please find the ArcGIS Experts (story tellers and developers) on this topic here: https://esri-es.github.io/arcgis-experts/?topic=d3
They don't work on the support team and some may even not work at Esri, but they are opening some projects and sharing insights related to this technology so we recommend you to follow them.
- d3 examples gallery
- Observable - Try D3 in a Notebook
- D3 playground - Tributary.io
- How to combine leaflet and d3 - Example 1
- How to combine leaflet and d3 - Example 2
Here you will find a lot of interesting resources to learn an improve your skills with d3.js: