diff --git a/src/common/catalog/catalog-category-registry.ts b/src/common/catalog/catalog-category-registry.ts
index 886db3e90a..a0319d773b 100644
--- a/src/common/catalog/catalog-category-registry.ts
+++ b/src/common/catalog/catalog-category-registry.ts
@@ -19,26 +19,38 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-import { action, computed, observable, toJS } from "mobx";
+import { action, computed, observable } from "mobx";
+import { Disposer, ExtendedMap } from "../utils";
 import { CatalogCategory, CatalogEntityData, CatalogEntityKindData } from "./catalog-entity";
 
 export class CatalogCategoryRegistry {
-  @observable protected categories: CatalogCategory[] = [];
+  protected categories = observable.set<CatalogCategory>();
 
-  @action add(category: CatalogCategory) {
-    this.categories.push(category);
+  @action add(category: CatalogCategory): Disposer {
+    this.categories.add(category);
+
+    return () => this.categories.delete(category);
   }
 
-  @action remove(category: CatalogCategory) {
-    this.categories = this.categories.filter((cat) => cat.apiVersion !== category.apiVersion && cat.kind !== category.kind);
+  @computed private get groupKindLookup(): Map<string, Map<string, CatalogCategory>> {
+    // ExtendedMap has the convenience methods `getOrInsert` and `strictSet`
+    const res = new ExtendedMap<string, ExtendedMap<string, CatalogCategory>>();
+
+    for (const category of this.categories) {
+      res
+        .getOrInsert(category.spec.group, ExtendedMap.new)
+        .strictSet(category.spec.names.kind, category);
+    }
+
+    return res;
   }
 
   @computed get items() {
-    return toJS(this.categories);
+    return Array.from(this.categories);
   }
 
-  getForGroupKind<T extends CatalogCategory>(group: string, kind: string) {
-    return this.categories.find((c) => c.spec.group === group && c.spec.names.kind === kind) as T;
+  getForGroupKind<T extends CatalogCategory>(group: string, kind: string): T | undefined {
+    return this.groupKindLookup.get(group)?.get(kind) as T;
   }
 
   getEntityForData(data: CatalogEntityData & CatalogEntityKindData) {
@@ -60,17 +72,11 @@ export class CatalogCategoryRegistry {
     return new specVersion.entityClass(data);
   }
 
-  getCategoryForEntity<T extends CatalogCategory>(data: CatalogEntityData & CatalogEntityKindData) {
+  getCategoryForEntity<T extends CatalogCategory>(data: CatalogEntityData & CatalogEntityKindData): T | undefined {
     const splitApiVersion = data.apiVersion.split("/");
     const group = splitApiVersion[0];
 
-    const category = this.categories.find((category) => {
-      return category.spec.group === group && category.spec.names.kind === data.kind;
-    });
-
-    if (!category) return null;
-
-    return category as T;
+    return this.getForGroupKind(group, data.kind);
   }
 }
 
diff --git a/src/common/utils/extended-map.ts b/src/common/utils/extended-map.ts
index 9d3a0dc7b3..c8b7ff4c65 100644
--- a/src/common/utils/extended-map.ts
+++ b/src/common/utils/extended-map.ts
@@ -22,19 +22,17 @@
 import { action, IEnhancer, IObservableMapInitialValues, ObservableMap } from "mobx";
 
 export class ExtendedMap<K, V> extends Map<K, V> {
-  constructor(protected getDefault: () => V, entries?: readonly (readonly [K, V])[] | null) {
-    super(entries);
+  static new<K, V>(entries?: readonly (readonly [K, V])[] | null): ExtendedMap<K, V> {
+    return new ExtendedMap<K, V>(entries);
   }
 
-  getOrInsert(key: K, val: V): V {
-    if (this.has(key)) {
-      return this.get(key);
-    }
-
-    return this.set(key, val).get(key);
-  }
-
-  getOrInsertWith(key: K, getVal: () => V): V {
+  /**
+   * Get the value behind `key`. If it was not pressent, first insert the value returned by `getVal`
+   * @param key The key to insert into the map with
+   * @param getVal A function that returns a new instance of `V`.
+   * @returns The value in the map
+   */
+  getOrInsert(key: K, getVal: () => V): V {
     if (this.has(key)) {
       return this.get(key);
     }
@@ -42,12 +40,29 @@ export class ExtendedMap<K, V> extends Map<K, V> {
     return this.set(key, getVal()).get(key);
   }
 
-  getOrDefault(key: K): V {
+  /**
+   * Set the value associated with `key` iff there was not a previous value
+   * @throws if `key` already in map
+   * @returns `this` so that `strictSet` can be chained
+   */
+  strictSet(key: K, val: V): this {
     if (this.has(key)) {
-      return this.get(key);
+      throw new TypeError("Duplicate key in map");
     }
 
-    return this.set(key, this.getDefault()).get(key);
+    return this.set(key, val);
+  }
+
+  /**
+   * Get the value associated with `key`
+   * @throws if `key` did not a value associated with it
+   */
+  strictGet(key: K): V {
+    if (!this.has(key)) {
+      throw new TypeError("key not in map");
+    }
+
+    return this.get(key);
   }
 }
 
diff --git a/src/renderer/api/__tests__/catalog-entity-registry.test.ts b/src/renderer/api/__tests__/catalog-entity-registry.test.ts
index 7cc208ad55..359b293993 100644
--- a/src/renderer/api/__tests__/catalog-entity-registry.test.ts
+++ b/src/renderer/api/__tests__/catalog-entity-registry.test.ts
@@ -42,7 +42,7 @@ describe("CatalogEntityRegistry", () => {
         spec: {}
       }];
 
-      catalog.updateItems(items);
+      (catalog as any).rawItems.replace(items);
       expect(catalog.items.length).toEqual(1);
 
       items.push({
@@ -60,7 +60,7 @@ describe("CatalogEntityRegistry", () => {
         spec: {}
       });
 
-      catalog.updateItems(items);
+      (catalog as any).rawItems.replace(items);
       expect(catalog.items.length).toEqual(2);
     });
 
@@ -81,13 +81,13 @@ describe("CatalogEntityRegistry", () => {
         spec: {}
       }];
 
-      catalog.updateItems(items);
+      (catalog as any).rawItems.replace(items);
       expect(catalog.items.length).toEqual(1);
       expect(catalog.items[0].status.phase).toEqual("disconnected");
 
       items[0].status.phase = "connected";
 
-      catalog.updateItems(items);
+      (catalog as any).rawItems.replace(items);
       expect(catalog.items.length).toEqual(1);
       expect(catalog.items[0].status.phase).toEqual("connected");
     });
@@ -125,9 +125,9 @@ describe("CatalogEntityRegistry", () => {
         }
       ];
 
-      catalog.updateItems(items);
+      (catalog as any).rawItems.replace(items);
       items.splice(0, 1);
-      catalog.updateItems(items);
+      (catalog as any).rawItems.replace(items);
       expect(catalog.items.length).toEqual(1);
       expect(catalog.items[0].metadata.uid).toEqual("456");
     });
diff --git a/src/renderer/api/catalog-entity-registry.ts b/src/renderer/api/catalog-entity-registry.ts
index 42c9b6f224..ac4e6748dc 100644
--- a/src/renderer/api/catalog-entity-registry.ts
+++ b/src/renderer/api/catalog-entity-registry.ts
@@ -19,28 +19,25 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-import { action, observable } from "mobx";
+import { computed, observable } from "mobx";
 import { broadcastMessage, subscribeToBroadcast } from "../../common/ipc";
 import { CatalogCategory, CatalogEntity, CatalogEntityData, catalogCategoryRegistry, CatalogCategoryRegistry, CatalogEntityKindData } from "../../common/catalog";
 import "../../common/catalog-entities";
+import { iter } from "../utils";
 
 export class CatalogEntityRegistry {
-  @observable protected _items: CatalogEntity[] = observable.array([], { deep: true });
+  protected rawItems = observable.array<CatalogEntityData & CatalogEntityKindData>([], { deep: true });
   @observable protected _activeEntity: CatalogEntity;
 
   constructor(private categoryRegistry: CatalogCategoryRegistry) {}
 
   init() {
     subscribeToBroadcast("catalog:items", (ev, items: (CatalogEntityData & CatalogEntityKindData)[]) => {
-      this.updateItems(items);
+      this.rawItems.replace(items);
     });
     broadcastMessage("catalog:broadcast");
   }
 
-  @action updateItems(items: (CatalogEntityData & CatalogEntityKindData)[]) {
-    this._items = items.map(data => this.categoryRegistry.getEntityForData(data));
-  }
-
   set activeEntity(entity: CatalogEntity) {
     this._activeEntity = entity;
   }
@@ -49,23 +46,27 @@ export class CatalogEntityRegistry {
     return this._activeEntity;
   }
 
-  get items() {
-    return this._items;
+  @computed get items() {
+    return Array.from(iter.filterMap(this.rawItems, rawItem => this.categoryRegistry.getEntityForData(rawItem)));
+  }
+
+  @computed get entities(): Map<string, CatalogEntity> {
+    return new Map(this.items.map(item => [item.metadata.uid, item]));
   }
 
   getById(id: string) {
-    return this._items.find((entity) => entity.metadata.uid === id);
+    return this.entities.get(id);
   }
 
   getItemsForApiKind<T extends CatalogEntity>(apiVersion: string, kind: string): T[] {
-    const items = this._items.filter((item) => item.apiVersion === apiVersion && item.kind === kind);
+    const items = this.items.filter((item) => item.apiVersion === apiVersion && item.kind === kind);
 
     return items as T[];
   }
 
   getItemsForCategory<T extends CatalogEntity>(category: CatalogCategory): T[] {
     const supportedVersions = category.spec.versions.map((v) => `${category.spec.group}/${v.name}`);
-    const items = this._items.filter((item) => supportedVersions.includes(item.apiVersion) && item.kind === category.spec.names.kind);
+    const items = this.items.filter((item) => supportedVersions.includes(item.apiVersion) && item.kind === category.spec.names.kind);
 
     return items as T[];
   }