FeatureReductionLayer

// clusters features based on their spatial proximity to other features
layer.featureReduction = {
  type: "cluster",
  clusterRadius: 100
};

// thins features in the view
layer.featureReduction = {
  type: "selection"
};

// Aggregates features to bins
layer.featureReduction = {
  type: "binning",
  renderer: {
    type: "simple",  // autocasts as new SimpleRenderer()
    symbol: {
      type: "simple-fill",  // autocasts as new SimpleFillSymbol()
      outline: {  // autocasts as new SimpleLineSymbol()
        width: 0.5,
        color: "white"
      }
    },
    visualVariables: [{
      type: "color",
      field: "aggregateCount",
      stops: [
        { value: 1, color: "white" },
        { value: 1000, color: "blue" }
      ]
    }]
  },
  popupTemplate: {
    content: "This bin contains <b>{aggregateCount}</b> features.",
    fieldInfos: [{
      fieldName: "aggregateCount",
      format: {
        digitSeparator: true,
        places: 0
      }
    }]
  }
};