diff --git a/.changeset/plenty-mirrors-bow.md b/.changeset/plenty-mirrors-bow.md
new file mode 100644
index 0000000000..d2686b60d3
--- /dev/null
+++ b/.changeset/plenty-mirrors-bow.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-catalog-backend': patch
+---
+
+Add experimental Prometheus metrics instrumentation to the catalog
diff --git a/packages/backend/package.json b/packages/backend/package.json
index b2877dedf5..8f0e84eac9 100644
--- a/packages/backend/package.json
+++ b/packages/backend/package.json
@@ -58,9 +58,11 @@
     "example-app": "^0.2.41",
     "express": "^4.17.1",
     "express-promise-router": "^4.1.0",
+    "express-prom-bundle": "^6.3.6",
     "knex": "^0.95.1",
     "pg": "^8.3.0",
     "pg-connection-string": "^2.3.0",
+    "prom-client": "^13.2.0",
     "sqlite3": "^5.0.1",
     "winston": "^3.2.1"
   },
diff --git a/packages/backend/src/index.ts b/packages/backend/src/index.ts
index aecb233581..78c6c4c20b 100644
--- a/packages/backend/src/index.ts
+++ b/packages/backend/src/index.ts
@@ -36,6 +36,7 @@ import {
 } from '@backstage/backend-common';
 import { Config } from '@backstage/config';
 import healthcheck from './plugins/healthcheck';
+import { metricsInit, metricsHandler } from './metrics';
 import auth from './plugins/auth';
 import catalog from './plugins/catalog';
 import codeCoverage from './plugins/codecoverage';
@@ -72,6 +73,7 @@ function makeCreateEnv(config: Config) {
 }
 
 async function main() {
+  metricsInit();
   const logger = getRootLogger();
 
   logger.info(
@@ -124,6 +126,7 @@ async function main() {
   const service = createServiceBuilder(module)
     .loadConfig(config)
     .addRouter('', await healthcheck(healthcheckEnv))
+    .addRouter('', metricsHandler())
     .addRouter('/api', apiRouter)
     .addRouter('', await app(appEnv));
 
diff --git a/packages/backend/src/metrics.ts b/packages/backend/src/metrics.ts
new file mode 100644
index 0000000000..8834022cd9
--- /dev/null
+++ b/packages/backend/src/metrics.ts
@@ -0,0 +1,63 @@
+/*
+ * Copyright 2021 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { useHotCleanup } from '@backstage/backend-common';
+import { RequestHandler, Request } from 'express';
+import promBundle from 'express-prom-bundle';
+import prom from 'prom-client';
+import * as url from 'url';
+
+/**
+ * Experimental Prometheus metrics used to benchmark the performance of the
+ * software catalog. Use this at your own risk.
+ */
+const rootRegEx = new RegExp('^/([^/]*)/.*');
+const apiRegEx = new RegExp('^/api/([^/]*)/.*');
+
+function normalizePath(req: Request): string {
+  const path = url.parse(req.originalUrl || req.url).pathname || '/';
+
+  // Capture /api/ and the plugin name
+  if (apiRegEx.test(path)) {
+    return path.replace(apiRegEx, '/api/$1');
+  }
+
+  // Only the first path segment at root level
+  return path.replace(rootRegEx, '/$1');
+}
+
+export function metricsInit(): void {
+  prom.collectDefaultMetrics({ prefix: 'backstage_' });
+}
+
+/**
+ * Adds a /metrics endpoint, register default runtime metrics and instrument the router.
+ */
+export function metricsHandler(): RequestHandler {
+  // We can only initialize the metrics once and have to clean them up between hot reloads
+  useHotCleanup(module, () => prom.register.clear());
+
+  return promBundle({
+    includeMethod: true,
+    includePath: true,
+    // Using includePath alone is problematic, as it will include path labels with high
+    // cardinality (e.g. path params). Instead we would have to template them. However, this
+    // is difficult, as every backend plugin might use different routes. Instead we only take
+    // the first directory of the path, to have at least an idea how each plugin performs:
+    normalizePath,
+    promClient: { collectDefaultMetrics: {} },
+  });
+}
diff --git a/plugins/catalog-backend/package.json b/plugins/catalog-backend/package.json
index f095f39785..c8b34015e2 100644
--- a/plugins/catalog-backend/package.json
+++ b/plugins/catalog-backend/package.json
@@ -51,8 +51,10 @@
     "glob": "^7.1.6",
     "knex": "^0.95.1",
     "lodash": "^4.17.15",
+    "luxon": "^2.0.2",
     "morgan": "^1.10.0",
     "p-limit": "^3.0.2",
+    "prom-client": "^13.2.0",
     "qs": "^6.9.4",
     "uuid": "^8.0.0",
     "winston": "^3.2.1",
diff --git a/plugins/catalog-backend/src/next/DefaultCatalogProcessingEngine.test.ts b/plugins/catalog-backend/src/next/DefaultCatalogProcessingEngine.test.ts
index 898ef08f6c..7d4d2ef8db 100644
--- a/plugins/catalog-backend/src/next/DefaultCatalogProcessingEngine.test.ts
+++ b/plugins/catalog-backend/src/next/DefaultCatalogProcessingEngine.test.ts
@@ -16,6 +16,7 @@
 
 import { getVoidLogger } from '@backstage/backend-common';
 import { Hash } from 'crypto';
+import { DateTime } from 'luxon';
 import waitForExpect from 'wait-for-expect';
 import { DefaultProcessingDatabase } from './database/DefaultProcessingDatabase';
 import { DefaultCatalogProcessingEngine } from './DefaultCatalogProcessingEngine';
@@ -84,7 +85,7 @@ describe('DefaultCatalogProcessingEngine', () => {
             },
             resultHash: '',
             state: new Map(),
-            nextUpdateAt: '',
+            nextUpdateAt: DateTime.now().toSQL(),
             lastDiscoveryAt: '',
           },
         ],
@@ -147,7 +148,7 @@ describe('DefaultCatalogProcessingEngine', () => {
             },
             resultHash: '',
             state: new Map(),
-            nextUpdateAt: '',
+            nextUpdateAt: DateTime.now().toSQL(),
             lastDiscoveryAt: '',
           },
         ],
@@ -181,7 +182,7 @@ describe('DefaultCatalogProcessingEngine', () => {
       unprocessedEntity: entity,
       resultHash: 'the matching hash',
       state: new Map(),
-      nextUpdateAt: '',
+      nextUpdateAt: DateTime.now().toSQL(),
       lastDiscoveryAt: '',
     };
 
diff --git a/plugins/catalog-backend/src/next/DefaultCatalogProcessingEngine.ts b/plugins/catalog-backend/src/next/DefaultCatalogProcessingEngine.ts
index 6468fa5187..41e81b1777 100644
--- a/plugins/catalog-backend/src/next/DefaultCatalogProcessingEngine.ts
+++ b/plugins/catalog-backend/src/next/DefaultCatalogProcessingEngine.ts
@@ -22,8 +22,10 @@ import {
 import { serializeError } from '@backstage/errors';
 import { Hash } from 'crypto';
 import stableStringify from 'fast-json-stable-stringify';
+import { DateTime } from 'luxon';
 import { Logger } from 'winston';
 import { ProcessingDatabase, RefreshStateItem } from './database/types';
+import { createCounterMetric, createSummaryMetric } from './metrics';
 import { CatalogProcessingOrchestrator } from './processing/types';
 import { Stitcher } from './stitching/Stitcher';
 import { startTaskPipeline } from './TaskPipeline';
@@ -84,6 +86,20 @@ class Connection implements EntityProviderConnection {
 
 export class DefaultCatalogProcessingEngine implements CatalogProcessingEngine {
   private stopFunc?: () => void;
+  private readonly metrics = {
+    processedEntities: createCounterMetric({
+      name: 'catalog_processed_entities_count',
+      help: 'Amount of entities processed',
+    }),
+    processingDuration: createSummaryMetric({
+      name: 'catalog_processing_duration_seconds',
+      help: 'Processing duration',
+    }),
+    processingQueueDelay: createSummaryMetric({
+      name: 'catalog_processing_queue_delay_seconds',
+      help: 'The amount of delay between being scheduled for processing, and the start of actually being processed',
+    }),
+  };
 
   constructor(
     private readonly logger: Logger,
@@ -95,6 +111,10 @@ export class DefaultCatalogProcessingEngine implements CatalogProcessingEngine {
   ) {}
 
   async start() {
+    if (this.stopFunc) {
+      throw new Error('Processing engine is already started');
+    }
+
     for (const provider of this.entityProviders) {
       await provider.connect(
         new Connection({
@@ -104,10 +124,6 @@ export class DefaultCatalogProcessingEngine implements CatalogProcessingEngine {
       );
     }
 
-    if (this.stopFunc) {
-      throw new Error('Processing engine is already started');
-    }
-
     this.stopFunc = startTaskPipeline<RefreshStateItem>({
       lowWatermark: 5,
       highWatermark: 10,
@@ -127,7 +143,16 @@ export class DefaultCatalogProcessingEngine implements CatalogProcessingEngine {
         }
       },
       processTask: async item => {
+        let endTimer;
         try {
+          this.metrics.processedEntities.inc(1);
+          this.metrics.processingQueueDelay.observe(
+            -DateTime.fromSQL(item.nextUpdateAt, { zone: 'UTC' })
+              .diffNow()
+              .as('seconds'),
+          );
+          endTimer = this.metrics.processingDuration.startTimer();
+
           const {
             id,
             state,
@@ -213,6 +238,8 @@ export class DefaultCatalogProcessingEngine implements CatalogProcessingEngine {
           await this.stitcher.stitch(setOfThingsToStitch);
         } catch (error) {
           this.logger.warn('Processing failed with:', error);
+        } finally {
+          endTimer?.();
         }
       },
     });
diff --git a/plugins/catalog-backend/src/next/database/DefaultProcessingDatabase.ts b/plugins/catalog-backend/src/next/database/DefaultProcessingDatabase.ts
index 203ca3efbf..7326a25a63 100644
--- a/plugins/catalog-backend/src/next/database/DefaultProcessingDatabase.ts
+++ b/plugins/catalog-backend/src/next/database/DefaultProcessingDatabase.ts
@@ -24,6 +24,7 @@ import type { Logger } from 'winston';
 import { Transaction } from '../../database';
 import { DeferredEntity } from '../processing/types';
 import { RefreshIntervalFunction } from '../refresh';
+import { initDatabaseMetrics } from './metrics';
 import {
   DbRefreshStateReferencesRow,
   DbRefreshStateRow,
@@ -51,7 +52,9 @@ export class DefaultProcessingDatabase implements ProcessingDatabase {
       logger: Logger;
       refreshInterval: RefreshIntervalFunction;
     },
-  ) {}
+  ) {
+    initDatabaseMetrics(options.database);
+  }
 
   async updateProcessedEntity(
     txOpaque: Transaction,
diff --git a/plugins/catalog-backend/src/next/database/metrics.ts b/plugins/catalog-backend/src/next/database/metrics.ts
new file mode 100644
index 0000000000..a41ad512f0
--- /dev/null
+++ b/plugins/catalog-backend/src/next/database/metrics.ts
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2021 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { Knex } from 'knex';
+import { DbLocationsRow } from '../../database/types';
+import { createGaugeMetric } from '../metrics';
+import { DbRefreshStateRow, DbRelationsRow } from './tables';
+
+export function initDatabaseMetrics(knex: Knex) {
+  const seen = new Set<string>();
+  return {
+    entities_count: createGaugeMetric({
+      name: 'catalog_entities_count',
+      help: 'Total amount of entities in the catalog',
+      labelNames: ['kind'],
+      async collect() {
+        const result = await knex<DbRefreshStateRow>('refresh_state').select(
+          'entity_ref',
+        );
+        const results = result
+          .map(row => row.entity_ref.split(':')[0])
+          .reduce((acc, e) => acc.set(e, (acc.get(e) || 0) + 1), new Map());
+
+        results.forEach((value, key) => {
+          seen.add(key);
+          this.set({ kind: key }, value);
+        });
+
+        // Set all the entities that were not seen to 0 and delete them from the seen set.
+        seen.forEach(key => {
+          if (!results.has(key)) {
+            this.set({ kind: key }, 0);
+            seen.delete(key);
+          }
+        });
+      },
+    }),
+    registered_locations: createGaugeMetric({
+      name: 'catalog_registered_locations_count',
+      help: 'Total amount of registered locations in the catalog',
+      async collect() {
+        const total = await knex<DbLocationsRow>('locations').count({
+          count: '*',
+        });
+        this.set(Number(total[0].count));
+      },
+    }),
+    relations: createGaugeMetric({
+      name: 'catalog_relations_count',
+      help: 'Total amount of relations between entities',
+      async collect() {
+        const total = await knex<DbRelationsRow>('relations').count({
+          count: '*',
+        });
+        this.set(Number(total[0].count));
+      },
+    }),
+  };
+}
diff --git a/plugins/catalog-backend/src/next/metrics.ts b/plugins/catalog-backend/src/next/metrics.ts
new file mode 100644
index 0000000000..4988af82ea
--- /dev/null
+++ b/plugins/catalog-backend/src/next/metrics.ts
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2021 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {
+  Counter,
+  CounterConfiguration,
+  Gauge,
+  GaugeConfiguration,
+  Histogram,
+  HistogramConfiguration,
+  register,
+  Summary,
+  SummaryConfiguration,
+} from 'prom-client';
+
+export function createCounterMetric<T extends string>(
+  config: CounterConfiguration<T>,
+): Counter<T> {
+  const existing = register.getSingleMetric(config.name) as Counter<T>;
+  return existing || new Counter<T>(config);
+}
+
+export function createGaugeMetric<T extends string>(
+  config: GaugeConfiguration<T>,
+): Gauge<T> {
+  const existing = register.getSingleMetric(config.name) as Gauge<T>;
+  return existing || new Gauge<T>(config);
+}
+
+export function createSummaryMetric<T extends string>(
+  config: SummaryConfiguration<T>,
+): Summary<T> {
+  const existing = register.getSingleMetric(config.name) as Summary<T>;
+  return existing || new Summary<T>(config);
+}
+
+export function createHistogramMetric<T extends string>(
+  config: HistogramConfiguration<T>,
+): Histogram<T> {
+  const existing = register.getSingleMetric(config.name) as Histogram<T>;
+  return existing || new Histogram<T>(config);
+}
diff --git a/yarn.lock b/yarn.lock
index 2fe37fc657..f86c3fd0b4 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -9446,6 +9446,11 @@ bindings@^1.5.0:
   dependencies:
     file-uri-to-path "1.0.0"
 
+bintrees@1.0.1:
+  version "1.0.1"
+  resolved "https://registry.npmjs.org/bintrees/-/bintrees-1.0.1.tgz#0e655c9b9c2435eaab68bf4027226d2b55a34524"
+  integrity sha1-DmVcm5wkNeqraL9AJyJtK1WjRSQ=
+
 bl@^4.0.3, bl@^4.1.0:
   version "4.1.0"
   resolved "https://registry.npmjs.org/bl/-/bl-4.1.0.tgz#451535264182bec2fbbc83a62ab98cf11d9f7b3a"
@@ -13475,6 +13480,14 @@ expect@^26.6.2:
     jest-message-util "^26.6.2"
     jest-regex-util "^26.0.0"
 
+express-prom-bundle@^6.3.6:
+  version "6.3.6"
+  resolved "https://registry.npmjs.org/express-prom-bundle/-/express-prom-bundle-6.3.6.tgz#c8da1c1024edfcc54953c365991aca57ffd0cfda"
+  integrity sha512-IRsTRCEKCVCHEriQlZ1FuutjEFc89KASsveXh+1HcGEnuZKiAC4LugxrsGEIdySqYvqOYSr2SWHJ6L8/BK2SHA==
+  dependencies:
+    on-finished "^2.3.0"
+    url-value-parser "^2.0.0"
+
 express-promise-router@^4.1.0:
   version "4.1.0"
   resolved "https://registry.npmjs.org/express-promise-router/-/express-promise-router-4.1.0.tgz#79160e145c27610ba411bceb0552a36f11dbab4f"
@@ -20451,7 +20464,7 @@ oidc-token-hash@^5.0.1:
   resolved "https://registry.npmjs.org/oidc-token-hash/-/oidc-token-hash-5.0.1.tgz#ae6beec3ec20f0fd885e5400d175191d6e2f10c6"
   integrity sha512-EvoOtz6FIEBzE+9q253HsLCVRiK/0doEJ2HCvvqMQb3dHZrP3WlJKYtJ55CRTw4jmYomzH4wkPuCj/I3ZvpKxQ==
 
-on-finished@~2.3.0:
+on-finished@^2.3.0, on-finished@~2.3.0:
   version "2.3.0"
   resolved "https://registry.npmjs.org/on-finished/-/on-finished-2.3.0.tgz#20f1336481b083cd75337992a16971aa2d906947"
   integrity sha1-IPEzZIGwg811M3mSoWlxqi2QaUc=
@@ -22089,6 +22102,13 @@ progress@^2.0.0:
   resolved "https://registry.npmjs.org/progress/-/progress-2.0.3.tgz#7e8cf8d8f5b8f239c1bc68beb4eb78567d572ef8"
   integrity sha512-7PiHtLll5LdnKIMw100I+8xJXR5gW2QwWYkT6iJva0bXitZKa/XMrSbdmg3r2Xnaidz9Qumd0VPaMrZlF9V9sA==
 
+prom-client@^13.2.0:
+  version "13.2.0"
+  resolved "https://registry.npmjs.org/prom-client/-/prom-client-13.2.0.tgz#99d13357912dd400f8911b77df19f7b328a93e92"
+  integrity sha512-wGr5mlNNdRNzEhRYXgboUU2LxHWIojxscJKmtG3R8f4/KiWqyYgXTLHs0+Ted7tG3zFT7pgHJbtomzZ1L0ARaQ==
+  dependencies:
+    tdigest "^0.1.1"
+
 promise-inflight@^1.0.1:
   version "1.0.1"
   resolved "https://registry.npmjs.org/promise-inflight/-/promise-inflight-1.0.1.tgz#98472870bf228132fcbdd868129bad12c3c029e3"
@@ -25669,6 +25689,13 @@ tarn@^3.0.1:
   resolved "https://registry.npmjs.org/tarn/-/tarn-3.0.1.tgz#ebac2c6dbc6977d34d4526e0a7814200386a8aec"
   integrity sha512-6usSlV9KyHsspvwu2duKH+FMUhqJnAh6J5J/4MITl8s94iSUQTLkJggdiewKv4RyARQccnigV48Z+khiuVZDJw==
 
+tdigest@^0.1.1:
+  version "0.1.1"
+  resolved "https://registry.npmjs.org/tdigest/-/tdigest-0.1.1.tgz#2e3cb2c39ea449e55d1e6cd91117accca4588021"
+  integrity sha1-Ljyyw56kSeVdHmzZEReszKRYgCE=
+  dependencies:
+    bintrees "1.0.1"
+
 teeny-request@^3.11.3:
   version "3.11.3"
   resolved "https://registry.npmjs.org/teeny-request/-/teeny-request-3.11.3.tgz#335c629f7645e5d6599362df2f3230c4cbc23a55"
@@ -26847,6 +26874,11 @@ url-parse@^1.4.3, url-parse@^1.5.1:
     querystringify "^2.1.1"
     requires-port "^1.0.0"
 
+url-value-parser@^2.0.0:
+  version "2.0.3"
+  resolved "https://registry.npmjs.org/url-value-parser/-/url-value-parser-2.0.3.tgz#cd4b8d6754e458d65e8125260c09718d926e6e21"
+  integrity sha512-FjIX+Q9lYmDM9uYIGdMYfQW0uLbWVwN2NrL2ayAI7BTOvEwzH+VoDdNquwB9h4dFAx+u6mb0ONLa3sHD5DvyvA==
+
 url@0.10.3:
   version "0.10.3"
   resolved "https://registry.npmjs.org/url/-/url-0.10.3.tgz#021e4d9c7705f21bbf37d03ceb58767402774c64"