Basemaps with different projections
Clustering - advanced configuration
FlowRenderer with effects and blending
ImageryTileLayer - shaded relief renderer
SceneLayerView - query statistics by geometry
Weather visualization
Dot density
Animate layer view effect
BasemapGallery widget
Edit features in 3D with the Editor widget
Edit features with the Editor widget
ElevationProfile Widget
You can also download the ArcGIS Maps SDK for JavaScript 4.30 single archive with all samples.