diff --git a/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig.js b/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig.js
new file mode 100644
index 0000000000000..ff4002b076e5d
--- /dev/null
+++ b/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig.js
@@ -0,0 +1,13 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+const { optimizeTsConfig } = require('./optimize_tsconfig/optimize');
+
+optimizeTsConfig().catch(err => {
+  console.error(err);
+  // eslint-disable-next-line no-process-exit
+  process.exit(1);
+});
diff --git a/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/README.md b/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/README.md
new file mode 100644
index 0000000000000..d3615d2870ef9
--- /dev/null
+++ b/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/README.md
@@ -0,0 +1,16 @@
+Hard forked from here:
+x-pack/legacy/plugins/apm/scripts/optimize-tsconfig.js
+
+
+#### Optimizing TypeScript 
+
+Kibana and X-Pack are very large TypeScript projects, and it comes at a cost. Editor responsiveness is not great, and the CLI type check for X-Pack takes about a minute. To get faster feedback, we create a smaller SIEM TypeScript project that only type checks the SIEM project and the files it uses. This optimization consists of creating a `tsconfig.json` in SIEM that includes the Kibana/X-Pack typings, and editing the Kibana/X-Pack configurations to not include any files, or removing the configurations altogether. The script configures git to ignore any changes in these files, and has an undo script as well.
+
+To run the optimization:
+
+`$ node x-pack/legacy/plugins/siem/scripts/optimize_tsconfig`
+
+To undo the optimization:
+
+`$ node x-pack/legacy/plugins/siem/scripts/unoptimize_tsconfig`
+
diff --git a/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/optimize.js b/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/optimize.js
new file mode 100644
index 0000000000000..9c04e0b69b738
--- /dev/null
+++ b/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/optimize.js
@@ -0,0 +1,76 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+/* eslint-disable import/no-extraneous-dependencies */
+
+const fs = require('fs');
+const { promisify } = require('util');
+const path = require('path');
+const json5 = require('json5');
+const execa = require('execa');
+
+const readFile = promisify(fs.readFile);
+const writeFile = promisify(fs.writeFile);
+
+const { xpackRoot, kibanaRoot, tsconfigTpl, filesToIgnore } = require('./paths');
+const { unoptimizeTsConfig } = require('./unoptimize');
+
+function prepareParentTsConfigs() {
+  return Promise.all(
+    [path.resolve(xpackRoot, 'tsconfig.json'), path.resolve(kibanaRoot, 'tsconfig.json')].map(
+      async filename => {
+        const config = json5.parse(await readFile(filename, 'utf-8'));
+
+        await writeFile(
+          filename,
+          JSON.stringify(
+            {
+              ...config,
+              include: [],
+            },
+            null,
+            2
+          ),
+          { encoding: 'utf-8' }
+        );
+      }
+    )
+  );
+}
+
+async function addFilesToXpackTsConfig() {
+  const template = json5.parse(await readFile(tsconfigTpl, 'utf-8'));
+  const xpackTsConfig = path.join(xpackRoot, 'tsconfig.json');
+  const config = json5.parse(await readFile(xpackTsConfig, 'utf-8'));
+
+  await writeFile(xpackTsConfig, JSON.stringify({ ...config, ...template }, null, 2), {
+    encoding: 'utf-8',
+  });
+}
+
+async function setIgnoreChanges() {
+  for (const filename of filesToIgnore) {
+    await execa('git', ['update-index', '--skip-worktree', filename]);
+  }
+}
+
+async function optimizeTsConfig() {
+  await unoptimizeTsConfig();
+
+  await prepareParentTsConfigs();
+
+  await addFilesToXpackTsConfig();
+
+  await setIgnoreChanges();
+  // eslint-disable-next-line no-console
+  console.log(
+    'Created an optimized tsconfig.json for SIEM. To undo these changes, run `./scripts/unoptimize_tsconfig.js`'
+  );
+}
+
+module.exports = {
+  optimizeTsConfig,
+};
diff --git a/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/paths.js b/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/paths.js
new file mode 100644
index 0000000000000..ca26203e17d2e
--- /dev/null
+++ b/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/paths.js
@@ -0,0 +1,23 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+const path = require('path');
+
+const xpackRoot = path.resolve(__dirname, '../../../../..');
+const kibanaRoot = path.resolve(xpackRoot, '..');
+
+const tsconfigTpl = path.resolve(__dirname, './tsconfig.json');
+
+const filesToIgnore = [
+  path.resolve(xpackRoot, 'tsconfig.json'),
+  path.resolve(kibanaRoot, 'tsconfig.json'),
+];
+
+module.exports = {
+  xpackRoot,
+  kibanaRoot,
+  tsconfigTpl,
+  filesToIgnore,
+};
diff --git a/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/tsconfig.json b/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/tsconfig.json
new file mode 100644
index 0000000000000..bec6988bdebd9
--- /dev/null
+++ b/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/tsconfig.json
@@ -0,0 +1,15 @@
+{
+  "include": [
+    "typings/**/*",
+    "plugins/siem/**/*",
+    "legacy/plugins/siem/**/*",
+    "plugins/apm/typings/numeral.d.ts",
+    "legacy/plugins/canvas/types/webpack.d.ts"
+  ],
+  "exclude": [
+    "test/**/*",
+    "**/__fixtures__/**/*",
+    "legacy/plugins/siem/cypress/**/*",
+    "**/typespec_tests.ts"
+  ]
+}
diff --git a/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/unoptimize.js b/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/unoptimize.js
new file mode 100644
index 0000000000000..21fc1aa2a1a33
--- /dev/null
+++ b/x-pack/legacy/plugins/siem/scripts/optimize_tsconfig/unoptimize.js
@@ -0,0 +1,25 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+/* eslint-disable import/no-extraneous-dependencies */
+
+const execa = require('execa');
+
+const { filesToIgnore } = require('./paths');
+
+async function unoptimizeTsConfig() {
+  for (const filename of filesToIgnore) {
+    await execa('git', ['update-index', '--no-skip-worktree', filename]);
+    await execa('git', ['checkout', filename]);
+  }
+}
+
+module.exports = {
+  unoptimizeTsConfig: async () => {
+    await unoptimizeTsConfig();
+    // eslint-disable-next-line no-console
+    console.log('Removed SIEM TypeScript optimizations');
+  },
+};
diff --git a/x-pack/legacy/plugins/siem/scripts/unoptimize_tsconfig.js b/x-pack/legacy/plugins/siem/scripts/unoptimize_tsconfig.js
new file mode 100644
index 0000000000000..d5392c76d9f8f
--- /dev/null
+++ b/x-pack/legacy/plugins/siem/scripts/unoptimize_tsconfig.js
@@ -0,0 +1,13 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+const { unoptimizeTsConfig } = require('./optimize_tsconfig/unoptimize');
+
+unoptimizeTsConfig().catch(err => {
+  console.error(err);
+  // eslint-disable-next-line no-process-exit
+  process.exit(1);
+});