diff --git a/eslint.config.js b/eslint.config.js
index 0607fe2ebca0..24853218a339 100644
--- a/eslint.config.js
+++ b/eslint.config.js
@@ -4,8 +4,17 @@ import svelte_config from '@sveltejs/eslint-config';
 export default [
 	...svelte_config,
 	{
+		languageOptions: {
+			parserOptions: {
+				project: true
+			}
+		},
 		rules: {
+			'@typescript-eslint/await-thenable': 'error',
+//			'@typescript-eslint/no-floating-promises': 'error',
+//			'@typescript-eslint/no-misused-promises': 'error',
 			'@typescript-eslint/no-unused-expressions': 'off',
+			'@typescript-eslint/require-await': 'error',
 			'no-undef': 'off'
 		}
 	},
@@ -15,7 +24,18 @@ export default [
 			'packages/adapter-static/test/apps/*/build',
 			'packages/adapter-cloudflare/files',
 			'packages/adapter-netlify/files',
-			'packages/adapter-node/files'
+			'packages/adapter-node/files',
+			'packages/adapter-node/rollup.config.js',
+			'packages/adapter-node/tests/smoke.spec.js',
+			'packages/adapter-static/test/apps',
+			'packages/create-svelte/shared',
+			'packages/create-svelte/templates',
+			'packages/kit/src/core/sync/create_manifest_data/test/samples',
+			'packages/kit/test/apps',
+			'packages/kit/test/build-errors',
+			'packages/kit/test/prerendering',
+			'packages/package/test/errors',
+			'packages/package/test/fixtures'
 		]
 	}
 ];
diff --git a/packages/adapter-auto/index.js b/packages/adapter-auto/index.js
index 983f6a1fa66c..fe720092bc79 100644
--- a/packages/adapter-auto/index.js
+++ b/packages/adapter-auto/index.js
@@ -36,9 +36,9 @@ function detect_package_manager() {
 }
 
 /** @param {string} name */
-async function import_from_cwd(name) {
+function import_from_cwd(name) {
 	const cwd = pathToFileURL(process.cwd()).href;
-	const url = await resolve(name, cwd + '/x.js');
+	const url = resolve(name, cwd + '/x.js');
 
 	return import(url);
 }
diff --git a/packages/adapter-netlify/index.js b/packages/adapter-netlify/index.js
index 7bfec980ef9a..8f8a1c5eecd4 100644
--- a/packages/adapter-netlify/index.js
+++ b/packages/adapter-netlify/index.js
@@ -92,7 +92,7 @@ export default function ({ split = false, edge = edge_set_in_env_var } = {}) {
 
 				await generate_edge_functions({ builder });
 			} else {
-				await generate_lambda_functions({ builder, split, publish });
+				generate_lambda_functions({ builder, split, publish });
 			}
 		},
 
@@ -182,7 +182,7 @@ async function generate_edge_functions({ builder }) {
  * @param { string } params.publish
  * @param { boolean } params.split
  */
-async function generate_lambda_functions({ builder, publish, split }) {
+function generate_lambda_functions({ builder, publish, split }) {
 	builder.mkdirp('.netlify/functions-internal/.svelte-kit');
 
 	/** @type {string[]} */
diff --git a/packages/adapter-node/src/handler.js b/packages/adapter-node/src/handler.js
index 5586e5169622..186232c31918 100644
--- a/packages/adapter-node/src/handler.js
+++ b/packages/adapter-node/src/handler.js
@@ -105,7 +105,7 @@ const ssr = async (req, res) => {
 		return;
 	}
 
-	setResponse(
+	await setResponse(
 		res,
 		await server.respond(request, {
 			platform: { req },
diff --git a/packages/adapter-vercel/files/serverless.js b/packages/adapter-vercel/files/serverless.js
index 1a76ba8a6f29..7928d148ec7c 100644
--- a/packages/adapter-vercel/files/serverless.js
+++ b/packages/adapter-vercel/files/serverless.js
@@ -35,7 +35,7 @@ export default async (req, res) => {
 
 	const request = await getRequest({ base: `https://${req.headers.host}`, request: req });
 
-	setResponse(
+	await setResponse(
 		res,
 		await server.respond(request, {
 			getClientAddress() {
diff --git a/packages/create-svelte/index.js b/packages/create-svelte/index.js
index b247b73a1fbb..be274e274337 100755
--- a/packages/create-svelte/index.js
+++ b/packages/create-svelte/index.js
@@ -3,6 +3,7 @@ import path from 'node:path';
 import { mkdirp, copy, dist } from './utils.js';
 
 /** @type {import('./types/index.js').create} */
+// eslint-disable-next-line @typescript-eslint/require-await
 export async function create(cwd, options) {
 	mkdirp(cwd);
 
diff --git a/packages/create-svelte/scripts/build-templates.js b/packages/create-svelte/scripts/build-templates.js
index 4e07dfa0fc99..7d7a47240507 100644
--- a/packages/create-svelte/scripts/build-templates.js
+++ b/packages/create-svelte/scripts/build-templates.js
@@ -305,4 +305,4 @@ async function main() {
 	await generate_templates(shared);
 }
 
-main();
+await main();
diff --git a/packages/create-svelte/test/check.js b/packages/create-svelte/test/check.js
index 91e5f3361713..b375090f8285 100644
--- a/packages/create-svelte/test/check.js
+++ b/packages/create-svelte/test/check.js
@@ -108,7 +108,7 @@ for (const template of templates) {
 		const cwd = path.join(test_workspace_dir, `${template}-${types}`);
 		fs.rmSync(cwd, { recursive: true, force: true });
 
-		create(cwd, {
+		await create(cwd, {
 			name: `create-svelte-test-${template}-${types}`,
 			template,
 			types,
diff --git a/packages/enhanced-img/src/index.js b/packages/enhanced-img/src/index.js
index bbdac4d9b5d7..97ca3e47073a 100644
--- a/packages/enhanced-img/src/index.js
+++ b/packages/enhanced-img/src/index.js
@@ -5,8 +5,9 @@ import { image } from './preprocessor.js';
 /**
  * @returns {Promise<import('vite').Plugin[]>}
  */
+// eslint-disable-next-line @typescript-eslint/require-await
 export async function enhancedImages() {
-	const imagetools_instance = await imagetools_plugin();
+	const imagetools_instance = imagetools_plugin();
 	return !process.versions.webcontainer
 		? [image_plugin(imagetools_instance), imagetools_instance]
 		: [];
@@ -60,7 +61,7 @@ const fallback = {
 	'.webp': 'png'
 };
 
-async function imagetools_plugin() {
+function imagetools_plugin() {
 	/** @type {Partial<import('vite-imagetools').VitePluginOptions>} */
 	const imagetools_opts = {
 		defaultDirectives: async ({ pathname, searchParams: qs }, metadata) => {
diff --git a/packages/enhanced-img/test/preprocessor.spec.js b/packages/enhanced-img/test/preprocessor.spec.js
index ba48b7c79531..7e25d4f8f643 100644
--- a/packages/enhanced-img/test/preprocessor.spec.js
+++ b/packages/enhanced-img/test/preprocessor.spec.js
@@ -32,7 +32,7 @@ it('Image preprocess snapshot test', async () => {
 	// Make imports readable
 	const ouput = processed.code.replace(/import/g, '\n\timport');
 
-	expect(ouput).toMatchFileSnapshot('./Output.svelte');
+	await expect(ouput).toMatchFileSnapshot('./Output.svelte');
 });
 
 it('parses a minimized object', () => {
diff --git a/packages/kit/postinstall.js b/packages/kit/postinstall.js
index da908bbf8537..8d6d9ed37b8e 100644
--- a/packages/kit/postinstall.js
+++ b/packages/kit/postinstall.js
@@ -40,7 +40,7 @@ try {
 
 			try {
 				const config = await load_config();
-				await sync.all(config, 'development');
+				sync.all(config, 'development');
 			} catch (error) {
 				console.error('Error while trying to sync SvelteKit config');
 				console.error(error);
diff --git a/packages/kit/src/cli.js b/packages/kit/src/cli.js
index 9cf2cfaf1afe..99c339844230 100755
--- a/packages/kit/src/cli.js
+++ b/packages/kit/src/cli.js
@@ -35,7 +35,7 @@ prog
 		try {
 			const config = await load_config();
 			const sync = await import('./core/sync/sync.js');
-			await sync.all_types(config, mode);
+			sync.all_types(config, mode);
 		} catch (error) {
 			handle_error(error);
 		}
diff --git a/packages/kit/src/core/postbuild/prerender.js b/packages/kit/src/core/postbuild/prerender.js
index f1633ab843af..20d32866836c 100644
--- a/packages/kit/src/core/postbuild/prerender.js
+++ b/packages/kit/src/core/postbuild/prerender.js
@@ -233,7 +233,7 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 
 		const body = Buffer.from(await response.arrayBuffer());
 
-		save('pages', response, body, decoded, encoded, referrer, 'linked');
+		await save('pages', response, body, decoded, encoded, referrer, 'linked');
 
 		for (const [dependency_path, result] of dependencies) {
 			// this seems circuitous, but using new URL allows us to not care
@@ -257,7 +257,7 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 
 			const body = result.body ?? new Uint8Array(await result.response.arrayBuffer());
 
-			save(
+			await save(
 				'dependencies',
 				result.response,
 				body,
@@ -305,7 +305,7 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 					/** @type {Set<string>} */ (expected_hashlinks.get(key)).add(decoded);
 				}
 
-				enqueue(decoded, decode_uri(pathname), pathname);
+				await enqueue(decoded, decode_uri(pathname), pathname);
 			}
 		}
 	}
@@ -319,7 +319,7 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 	 * @param {string | null} referrer
 	 * @param {'linked' | 'fetched'} referenceType
 	 */
-	function save(category, response, body, decoded, encoded, referrer, referenceType) {
+	async function save(category, response, body, decoded, encoded, referrer, referenceType) {
 		const response_type = Math.floor(response.status / 100);
 		const headers = Object.fromEntries(response.headers);
 
@@ -341,7 +341,7 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 			if (location) {
 				const resolved = resolve(encoded, location);
 				if (is_root_relative(resolved)) {
-					enqueue(decoded, decode_uri(resolved), resolved);
+					await enqueue(decoded, decode_uri(resolved), resolved);
 				}
 
 				if (!headers['x-sveltekit-normalize']) {
@@ -449,6 +449,7 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 		read: (file) => createReadableStream(`${config.outDir}/output/server/${file}`)
 	});
 
+	const entries_to_enqueue = [];
 	for (const entry of config.prerender.entries) {
 		if (entry === '*') {
 			for (const [id, prerender] of prerender_map) {
@@ -459,19 +460,20 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 
 					if (processed_id.includes('[')) continue;
 					const path = `/${get_route_segments(processed_id).join('/')}`;
-					enqueue(null, config.paths.base + path);
+					entries_to_enqueue.push({ path: config.paths.base + path });
 				}
 			}
 		} else {
-			enqueue(null, config.paths.base + entry);
+			entries_to_enqueue.push({ path: config.paths.base + entry });
 		}
 	}
 
 	for (const { id, entries } of route_level_entries) {
 		for (const entry of entries) {
-			enqueue(null, config.paths.base + entry, undefined, id);
+			entries_to_enqueue.push({ path: config.paths.base + entry, id });
 		}
 	}
+	await Promise.all(entries_to_enqueue.map(({ path, id }) => enqueue(null, path, undefined, id)));
 
 	await q.done();
 
diff --git a/packages/kit/src/core/sync/sync.js b/packages/kit/src/core/sync/sync.js
index d16466818f40..fac716f88371 100644
--- a/packages/kit/src/core/sync/sync.js
+++ b/packages/kit/src/core/sync/sync.js
@@ -23,7 +23,7 @@ export function init(config, mode) {
  * Update SvelteKit's generated files
  * @param {import('types').ValidatedConfig} config
  */
-export async function create(config) {
+export function create(config) {
 	const manifest_data = create_manifest_data({ config });
 
 	const output = path.join(config.kit.outDir, 'generated');
@@ -31,7 +31,7 @@ export async function create(config) {
 	write_client_manifest(config.kit, manifest_data, `${output}/client`);
 	write_server(config, output);
 	write_root(manifest_data, output);
-	await write_all_types(config, manifest_data);
+	write_all_types(config, manifest_data);
 
 	return { manifest_data };
 }
@@ -44,8 +44,8 @@ export async function create(config) {
  * @param {import('types').ManifestData} manifest_data
  * @param {string} file
  */
-export async function update(config, manifest_data, file) {
-	await write_types(config, manifest_data, file);
+export function update(config, manifest_data, file) {
+	write_types(config, manifest_data, file);
 
 	return { manifest_data };
 }
@@ -55,9 +55,9 @@ export async function update(config, manifest_data, file) {
  * @param {import('types').ValidatedConfig} config
  * @param {string} mode The Vite mode
  */
-export async function all(config, mode) {
+export function all(config, mode) {
 	init(config, mode);
-	return await create(config);
+	return create(config);
 }
 
 /**
@@ -65,10 +65,10 @@ export async function all(config, mode) {
  * @param {import('types').ValidatedConfig} config
  * @param {string} mode The Vite mode
  */
-export async function all_types(config, mode) {
+export function all_types(config, mode) {
 	init(config, mode);
 	const manifest_data = create_manifest_data({ config });
-	await write_all_types(config, manifest_data);
+	write_all_types(config, manifest_data);
 }
 
 /**
diff --git a/packages/kit/src/core/sync/write_types/index.js b/packages/kit/src/core/sync/write_types/index.js
index 2c2f0fa0b5b3..778f338260c3 100644
--- a/packages/kit/src/core/sync/write_types/index.js
+++ b/packages/kit/src/core/sync/write_types/index.js
@@ -28,7 +28,7 @@ const cwd = process.cwd();
  * @param {import('types').ValidatedConfig} config
  * @param {import('types').ManifestData} manifest_data
  */
-export async function write_all_types(config, manifest_data) {
+export function write_all_types(config, manifest_data) {
 	if (!ts) return;
 
 	const types_dir = `${config.kit.outDir}/types`;
@@ -133,7 +133,7 @@ export async function write_all_types(config, manifest_data) {
  * @param {import('types').ManifestData} manifest_data
  * @param {string} file
  */
-export async function write_types(config, manifest_data, file) {
+export function write_types(config, manifest_data, file) {
 	if (!ts) return;
 
 	if (!path.basename(file).startsWith('+')) {
diff --git a/packages/kit/src/core/sync/write_types/index.spec.js b/packages/kit/src/core/sync/write_types/index.spec.js
index d50a4d12fa82..24fef7441e1f 100644
--- a/packages/kit/src/core/sync/write_types/index.spec.js
+++ b/packages/kit/src/core/sync/write_types/index.spec.js
@@ -12,7 +12,7 @@ const cwd = fileURLToPath(new URL('./test', import.meta.url));
 /**
  * @param {string} dir
  */
-async function run_test(dir) {
+function run_test(dir) {
 	rimraf(path.join(cwd, dir, '.svelte-kit'));
 
 	const initial = options({}, 'config');
@@ -25,22 +25,22 @@ async function run_test(dir) {
 	const manifest = create_manifest_data({
 		config: /** @type {import('types').ValidatedConfig} */ (initial)
 	});
-	await write_all_types(initial, manifest);
+	write_all_types(initial, manifest);
 }
 
-test('Creates correct $types', async () => {
+test('Creates correct $types', () => {
 	// To save us from creating a real SvelteKit project for each of the tests,
 	// we first run the type generation directly for each test case, and then
 	// call `tsc` to check that the generated types are valid.
-	await run_test('actions');
-	await run_test('simple-page-shared-only');
-	await run_test('simple-page-server-only');
-	await run_test('simple-page-server-and-shared');
-	await run_test('layout');
-	await run_test('layout-advanced');
-	await run_test('slugs');
-	await run_test('slugs-layout-not-all-pages-have-load');
-	await run_test('param-type-inference');
+	run_test('actions');
+	run_test('simple-page-shared-only');
+	run_test('simple-page-server-only');
+	run_test('simple-page-server-and-shared');
+	run_test('layout');
+	run_test('layout-advanced');
+	run_test('slugs');
+	run_test('slugs-layout-not-all-pages-have-load');
+	run_test('param-type-inference');
 	try {
 		execSync('pnpm testtypes', { cwd });
 	} catch (e) {
diff --git a/packages/kit/src/exports/hooks/sequence.spec.js b/packages/kit/src/exports/hooks/sequence.spec.js
index a4912bdd5790..0829e90a92e6 100644
--- a/packages/kit/src/exports/hooks/sequence.spec.js
+++ b/packages/kit/src/exports/hooks/sequence.spec.js
@@ -120,7 +120,7 @@ test('uses first defined preload option', async () => {
 	const event = /** @type {import('@sveltejs/kit').RequestEvent} */ ({});
 	const response = await handler({
 		event,
-		resolve: async (_event, opts = {}) => {
+		resolve: (_event, opts = {}) => {
 			let html = '';
 
 			const { preload = () => false } = opts;
@@ -153,7 +153,7 @@ test('uses first defined filterSerializedResponseHeaders option', async () => {
 	const event = /** @type {import('@sveltejs/kit').RequestEvent} */ ({});
 	const response = await handler({
 		event,
-		resolve: async (_event, opts = {}) => {
+		resolve: (_event, opts = {}) => {
 			let html = '';
 
 			const { filterSerializedResponseHeaders = () => false } = opts;
diff --git a/packages/kit/src/exports/node/index.js b/packages/kit/src/exports/node/index.js
index 77f2a0354ad6..d59fff34efb9 100644
--- a/packages/kit/src/exports/node/index.js
+++ b/packages/kit/src/exports/node/index.js
@@ -103,6 +103,7 @@ function get_raw_body(req, body_size_limit) {
  * }} options
  * @returns {Promise<Request>}
  */
+// eslint-disable-next-line @typescript-eslint/require-await
 export async function getRequest({ request, base, bodySizeLimit }) {
 	return new Request(base + request.url, {
 		// @ts-expect-error
@@ -121,6 +122,7 @@ export async function getRequest({ request, base, bodySizeLimit }) {
  * @param {Response} response
  * @returns {Promise<void>}
  */
+// eslint-disable-next-line @typescript-eslint/require-await
 export async function setResponse(res, response) {
 	for (const [key, value] of response.headers) {
 		try {
diff --git a/packages/kit/src/exports/vite/build/build_service_worker.js b/packages/kit/src/exports/vite/build/build_service_worker.js
index cd594cdad096..a7c11188d02a 100644
--- a/packages/kit/src/exports/vite/build/build_service_worker.js
+++ b/packages/kit/src/exports/vite/build/build_service_worker.js
@@ -66,13 +66,13 @@ export async function build_service_worker(
 	 */
 	const sw_virtual_modules = {
 		name: 'service-worker-build-virtual-modules',
-		async resolveId(id) {
+		resolveId(id) {
 			if (id.startsWith('$env/') || id.startsWith('$app/') || id === '$service-worker') {
 				return `\0virtual:${id}`;
 			}
 		},
 
-		async load(id) {
+		load(id) {
 			if (!id.startsWith('\0virtual:')) return;
 
 			if (id === service_worker) {
diff --git a/packages/kit/src/exports/vite/dev/index.js b/packages/kit/src/exports/vite/dev/index.js
index 503cb51feb45..1c6792e431b9 100644
--- a/packages/kit/src/exports/vite/dev/index.js
+++ b/packages/kit/src/exports/vite/dev/index.js
@@ -97,9 +97,9 @@ export async function dev(vite, vite_config, svelte_config) {
 		return { module, module_node, url };
 	}
 
-	async function update_manifest() {
+	function update_manifest() {
 		try {
-			({ manifest_data } = await sync.create(svelte_config));
+			({ manifest_data } = sync.create(svelte_config));
 
 			if (manifest_error) {
 				manifest_error = null;
@@ -273,7 +273,7 @@ export async function dev(vite, vite_config, svelte_config) {
 		return error.stack;
 	}
 
-	await update_manifest();
+	update_manifest();
 
 	/**
 	 * @param {string} event
@@ -377,7 +377,7 @@ export async function dev(vite, vite_config, svelte_config) {
 			SvelteKitError: control_module_vite.SvelteKitError
 		});
 	}
-	align_exports();
+	await align_exports();
 	const ws_send = vite.ws.send;
 	/** @param {any} args */
 	vite.ws.send = function (...args) {
@@ -389,7 +389,7 @@ export async function dev(vite, vite_config, svelte_config) {
 		return ws_send.apply(vite.ws, args);
 	};
 
-	vite.middlewares.use(async (req, res, next) => {
+	vite.middlewares.use((req, res, next) => {
 		try {
 			const base = `${vite.config.server.https ? 'https' : 'http'}://${
 				req.headers[':authority'] || req.headers.host
@@ -540,7 +540,7 @@ export async function dev(vite, vite_config, svelte_config) {
 						setResponse(res, rendered);
 					});
 				} else {
-					setResponse(res, rendered);
+					await setResponse(res, rendered);
 				}
 			} catch (e) {
 				const error = coalesce_to_error(e);
diff --git a/packages/kit/src/exports/vite/index.js b/packages/kit/src/exports/vite/index.js
index 81689ddb91da..402fa009bf64 100644
--- a/packages/kit/src/exports/vite/index.js
+++ b/packages/kit/src/exports/vite/index.js
@@ -131,7 +131,7 @@ const warning_preprocessor = {
 async function resolve_peer_dependency(dependency) {
 	try {
 		// @ts-expect-error the types are wrong
-		const resolved = await imr.resolve(dependency, pathToFileURL(process.cwd() + '/dummy.js'));
+		const resolved = imr.resolve(dependency, pathToFileURL(process.cwd() + '/dummy.js'));
 		return import(resolved);
 	} catch {
 		throw new Error(
@@ -242,7 +242,7 @@ async function kit({ svelte_config }) {
 		 * Build the SvelteKit-provided Vite config to be merged with the user's vite.config.js file.
 		 * @see https://vitejs.dev/guide/api-plugin.html#config
 		 */
-		async config(config, config_env) {
+		config(config, config_env) {
 			initial_config = config;
 			vite_config_env = config_env;
 			is_build = config_env.command === 'build';
@@ -339,7 +339,7 @@ async function kit({ svelte_config }) {
 				};
 
 				if (!secondary_build_started) {
-					manifest_data = (await sync.all(svelte_config, config_env.mode)).manifest_data;
+					manifest_data = sync.all(svelte_config, config_env.mode).manifest_data;
 				}
 			} else {
 				new_config.define = {
@@ -373,7 +373,7 @@ async function kit({ svelte_config }) {
 	const plugin_virtual_modules = {
 		name: 'vite-plugin-sveltekit-virtual-modules',
 
-		async resolveId(id, importer) {
+		resolveId(id, importer) {
 			// If importing from a service-worker, only allow $service-worker & $env/static/public, but none of the other virtual modules.
 			// This check won't catch transitive imports, but it will warn when the import comes from a service-worker directly.
 			// Transitive imports will be caught during the build.
@@ -397,7 +397,7 @@ async function kit({ svelte_config }) {
 			}
 		},
 
-		async load(id, options) {
+		load(id, options) {
 			const browser = !options?.ssr;
 
 			const global = is_build
@@ -533,7 +533,7 @@ async function kit({ svelte_config }) {
 
 		writeBundle: {
 			sequential: true,
-			async handler(_options) {
+			handler(_options) {
 				if (vite_config.build.ssr) return;
 
 				const guard = module_guard(this, {
@@ -560,7 +560,7 @@ async function kit({ svelte_config }) {
 		 * Build the SvelteKit-provided Vite config to be merged with the user's vite.config.js file.
 		 * @see https://vitejs.dev/guide/api-plugin.html#config
 		 */
-		async config(config) {
+		config(config) {
 			/** @type {import('vite').UserConfig} */
 			let new_config;
 
diff --git a/packages/kit/src/runtime/app/forms.js b/packages/kit/src/runtime/app/forms.js
index d55783116a97..da7245d1605a 100644
--- a/packages/kit/src/runtime/app/forms.js
+++ b/packages/kit/src/runtime/app/forms.js
@@ -104,7 +104,7 @@ export function enhance(form_element, submit = () => {}) {
 			result.type === 'redirect' ||
 			result.type === 'error'
 		) {
-			applyAction(result);
+			await applyAction(result);
 		}
 	};
 
@@ -179,7 +179,7 @@ export function enhance(form_element, submit = () => {}) {
 			result = { type: 'error', error };
 		}
 
-		callback({
+		await callback({
 			action,
 			formData: form_data,
 			formElement: form_element,
diff --git a/packages/kit/src/runtime/client/client.js b/packages/kit/src/runtime/client/client.js
index df0148d4e75c..ab1ec548f9ae 100644
--- a/packages/kit/src/runtime/client/client.js
+++ b/packages/kit/src/runtime/client/client.js
@@ -255,13 +255,6 @@ export async function start(_app, _target, hydrate) {
 	container = __SVELTEKIT_EMBEDDED__ ? _target : document.documentElement;
 	target = _target;
 
-	// we import the root layout/error nodes eagerly, so that
-	// connectivity errors after initialisation don't nuke the app
-	default_layout_loader = _app.nodes[0];
-	default_error_loader = _app.nodes[1];
-	default_layout_loader();
-	default_error_loader();
-
 	current_history_index = history.state?.[HISTORY_INDEX];
 	current_navigation_index = history.state?.[NAVIGATION_INDEX];
 
@@ -289,11 +282,15 @@ export async function start(_app, _target, hydrate) {
 		scrollTo(scroll.x, scroll.y);
 	}
 
-	if (hydrate) {
-		await _hydrate(target, hydrate);
-	} else {
-		goto(location.href, { replaceState: true });
-	}
+	// we import the root layout/error nodes eagerly, so that
+	// connectivity errors after initialisation don't nuke the app
+	default_layout_loader = _app.nodes[0];
+	default_error_loader = _app.nodes[1];
+	await Promise.allSettled([
+		default_layout_loader(),
+		default_error_loader(),
+		hydrate ? _hydrate(target, hydrate) : goto(location.href, { replaceState: true })
+	]);
 
 	_start_router();
 }
@@ -469,15 +466,7 @@ function initialize(result, target, hydrate) {
  *   form?: Record<string, any> | null;
  * }} opts
  */
-async function get_navigation_result_from_branch({
-	url,
-	params,
-	branch,
-	status,
-	error,
-	route,
-	form
-}) {
+function get_navigation_result_from_branch({ url, params, branch, status, error, route, form }) {
 	/** @type {import('types').TrailingSlash} */
 	let slash = 'never';
 
@@ -1017,7 +1006,7 @@ async function load_route({ id, invalidating, url, params, route, preload }) {
 
 				const error_load = await load_nearest_error_page(i, branch, errors);
 				if (error_load) {
-					return await get_navigation_result_from_branch({
+					return get_navigation_result_from_branch({
 						url,
 						params,
 						branch: branch.slice(0, error_load.idx).concat(error_load.node),
@@ -1036,7 +1025,7 @@ async function load_route({ id, invalidating, url, params, route, preload }) {
 		}
 	}
 
-	return await get_navigation_result_from_branch({
+	return get_navigation_result_from_branch({
 		url,
 		params,
 		branch,
@@ -1136,7 +1125,7 @@ async function load_root_error_page({ status, error, url, route }) {
 		data: null
 	};
 
-	return await get_navigation_result_from_branch({
+	return get_navigation_result_from_branch({
 		url,
 		params,
 		branch: [root_layout, root_error],
@@ -1327,7 +1316,7 @@ async function navigate({
 				route: { id: null }
 			});
 		} else {
-			_goto(new URL(navigation_result.location, url).href, {}, redirect_count + 1, nav_token);
+			await _goto(new URL(navigation_result.location, url).href, {}, redirect_count + 1, nav_token);
 			return false;
 		}
 	} else if (/** @type {number} */ (navigation_result.props.page.status) >= 400) {
@@ -1525,10 +1514,10 @@ function setup_preload() {
 	container.addEventListener('touchstart', tap, { passive: true });
 
 	const observer = new IntersectionObserver(
-		(entries) => {
+		async (entries) => {
 			for (const entry of entries) {
 				if (entry.isIntersecting) {
-					_preload_code(/** @type {HTMLAnchorElement} */ (entry.target).href);
+					await _preload_code(/** @type {HTMLAnchorElement} */ (entry.target).href);
 					observer.unobserve(entry.target);
 				}
 			}
@@ -1942,7 +1931,7 @@ export async function applyAction(result) {
 
 		const error_load = await load_nearest_error_page(current.branch.length, branch, route.errors);
 		if (error_load) {
-			const navigation_result = await get_navigation_result_from_branch({
+			const navigation_result = get_navigation_result_from_branch({
 				url,
 				params: current.params,
 				branch: branch.slice(0, error_load.idx).concat(error_load.node),
@@ -1958,7 +1947,7 @@ export async function applyAction(result) {
 			tick().then(reset_focus);
 		}
 	} else if (result.type === 'redirect') {
-		_goto(result.location, { invalidateAll: true }, 0);
+		await _goto(result.location, { invalidateAll: true }, 0);
 	} else {
 		/** @type {Record<string, any>} */
 		root.$set({
@@ -2130,7 +2119,7 @@ function _start_router() {
 			setTimeout(fulfil, 100); // fallback for edge case where rAF doesn't fire because e.g. tab was backgrounded
 		});
 
-		navigate({
+		await navigate({
 			type: 'link',
 			url,
 			keepfocus: options.keepfocus,
@@ -2364,7 +2353,7 @@ async function _hydrate(
 			}
 		}
 
-		result = await get_navigation_result_from_branch({
+		result = get_navigation_result_from_branch({
 			url,
 			params,
 			branch,
diff --git a/packages/kit/src/runtime/client/fetcher.js b/packages/kit/src/runtime/client/fetcher.js
index 46d7a0b569a3..dd964c8144ba 100644
--- a/packages/kit/src/runtime/client/fetcher.js
+++ b/packages/kit/src/runtime/client/fetcher.js
@@ -18,12 +18,13 @@ export function unlock_fetch() {
 if (DEV && BROWSER) {
 	let can_inspect_stack_trace = false;
 
-	// detect whether async stack traces work
+	// eslint-disable-next-line @typescript-eslint/require-await
 	const check_stack_trace = async () => {
 		const stack = /** @type {string} */ (new Error().stack);
 		can_inspect_stack_trace = stack.includes('check_stack_trace');
 	};
 
+	// detect whether async stack traces work
 	check_stack_trace();
 
 	/**
diff --git a/packages/kit/src/runtime/client/utils.js b/packages/kit/src/runtime/client/utils.js
index d205f48cdc42..16a1b3426a9e 100644
--- a/packages/kit/src/runtime/client/utils.js
+++ b/packages/kit/src/runtime/client/utils.js
@@ -240,6 +240,7 @@ export function create_updated_store() {
 	if (DEV || !BROWSER) {
 		return {
 			subscribe,
+			// eslint-disable-next-line @typescript-eslint/require-await
 			check: async () => false
 		};
 	}
diff --git a/packages/kit/src/runtime/server/page/index.js b/packages/kit/src/runtime/server/page/index.js
index b90bf67eef58..3424c5fcdce5 100644
--- a/packages/kit/src/runtime/server/page/index.js
+++ b/packages/kit/src/runtime/server/page/index.js
@@ -146,7 +146,7 @@ export async function render_page(event, page, options, manifest, state, resolve
 							const data = {};
 							for (let j = 0; j < i; j += 1) {
 								const parent = await server_promises[j];
-								if (parent) Object.assign(data, await parent.data);
+								if (parent) Object.assign(data, parent.data);
 							}
 							return data;
 						}
diff --git a/packages/kit/src/runtime/server/page/load_data.spec.js b/packages/kit/src/runtime/server/page/load_data.spec.js
index ec3167c08822..da5cc0b17203 100644
--- a/packages/kit/src/runtime/server/page/load_data.spec.js
+++ b/packages/kit/src/runtime/server/page/load_data.spec.js
@@ -5,6 +5,7 @@ import { create_universal_fetch } from './load_data.js';
  * @param {Partial<Pick<import('@sveltejs/kit').RequestEvent, 'fetch' | 'url' | 'request' | 'route'>>} event
  */
 function create_fetch(event) {
+	// eslint-disable-next-line @typescript-eslint/require-await
 	event.fetch = event.fetch || (async () => new Response('foo'));
 	event.request = event.request || new Request('doesnt:matter');
 	event.route = event.route || { id: 'foo' };
@@ -38,6 +39,7 @@ test('keeps body when mode isnt no-cors on same domain', async () => {
 
 test('succeeds when acao header present on cors', async () => {
 	const fetch = create_fetch({
+		// eslint-disable-next-line @typescript-eslint/require-await
 		fetch: async () => new Response('foo', { headers: { 'access-control-allow-origin': '*' } })
 	});
 	const response = await fetch('https://domain-a.com');
@@ -48,7 +50,7 @@ test('succeeds when acao header present on cors', async () => {
 test('errors when no acao header present on cors', async () => {
 	const fetch = create_fetch({});
 
-	expect(async () => {
+	await expect(async () => {
 		const response = await fetch('https://domain-b.com');
 		await response.text();
 	}).rejects.toThrowError(
diff --git a/packages/kit/src/runtime/server/page/respond_with_error.js b/packages/kit/src/runtime/server/page/respond_with_error.js
index 121ebc5406f2..10bf3fe0d324 100644
--- a/packages/kit/src/runtime/server/page/respond_with_error.js
+++ b/packages/kit/src/runtime/server/page/respond_with_error.js
@@ -50,6 +50,7 @@ export async function respond_with_error({
 				event,
 				state,
 				node: default_layout,
+				// eslint-disable-next-line @typescript-eslint/require-await
 				parent: async () => ({})
 			});
 
@@ -59,6 +60,7 @@ export async function respond_with_error({
 				event,
 				fetched,
 				node: default_layout,
+				// eslint-disable-next-line @typescript-eslint/require-await
 				parent: async () => ({}),
 				resolve_opts,
 				server_data_promise,
diff --git a/packages/kit/src/utils/fork.js b/packages/kit/src/utils/fork.js
index 96d513a21e6f..28dc8a798853 100644
--- a/packages/kit/src/utils/fork.js
+++ b/packages/kit/src/utils/fork.js
@@ -7,7 +7,7 @@ import { Worker, parentPort } from 'node:worker_threads';
  * @template T
  * @template U
  * @param {string} module `import.meta.url` of the file
- * @param {(opts: T) => U} callback The function that is invoked in the subprocess
+ * @param {(opts: T) => Promise<U>} callback The function that is invoked in the subprocess
  * @returns {(opts: T) => Promise<U>} A function that when called starts the subprocess
  */
 export function forked(module, callback) {
diff --git a/packages/kit/src/utils/streaming.spec.js b/packages/kit/src/utils/streaming.spec.js
index e9fb58004abd..379dd7cc12cb 100644
--- a/packages/kit/src/utils/streaming.spec.js
+++ b/packages/kit/src/utils/streaming.spec.js
@@ -1,12 +1,19 @@
 import { expect, test } from 'vitest';
 import { create_async_iterator } from './streaming.js';
+import { fail } from 'node:assert';
 
 test('works with fast consecutive promise resolutions', async () => {
 	const iterator = create_async_iterator();
 
-	Promise.resolve(1).then((n) => iterator.push(n));
-	Promise.resolve(2).then((n) => iterator.push(n));
-	Promise.resolve().then(() => iterator.done());
+	Promise.resolve(1)
+		.then((n) => iterator.push(n))
+		.catch(fail);
+	Promise.resolve(2)
+		.then((n) => iterator.push(n))
+		.catch(fail);
+	Promise.resolve()
+		.then(() => iterator.done())
+		.catch(fail);
 
 	const actual = [];
 	for await (const value of iterator.iterator) {
diff --git a/packages/kit/test/utils.js b/packages/kit/test/utils.js
index 38e4faaedd6c..92616c3e42ad 100644
--- a/packages/kit/test/utils.js
+++ b/packages/kit/test/utils.js
@@ -7,7 +7,7 @@ import { test as base, devices } from '@playwright/test';
 export const test = base.extend({
 	app: async ({ page }, use) => {
 		// these are assumed to have been put in the global scope by the layout
-		use({
+		await use({
 			/**
 			 * @param {string} url
 			 * @param {{ replaceState?: boolean }} opts
@@ -66,7 +66,7 @@ export const test = base.extend({
 			}
 		}
 
-		use(clicknav);
+		await use(clicknav);
 	},
 
 	in_view: async ({ page }, use) => {
@@ -77,7 +77,7 @@ export const test = base.extend({
 			return box && view && box.y < view.height && box.y + box.height > 0;
 		}
 
-		use(in_view);
+		await use(in_view);
 	},
 
 	get_computed_style: async ({ page }, use) => {
@@ -119,7 +119,7 @@ export const test = base.extend({
 	},
 
 	// eslint-disable-next-line no-empty-pattern
-	read_errors: ({}, use) => {
+	read_errors: async ({}, use) => {
 		/** @param {string} path */
 		function read_errors(path) {
 			const errors =
@@ -128,7 +128,7 @@ export const test = base.extend({
 			return errors[path];
 		}
 
-		use(read_errors);
+		await use(read_errors);
 	},
 
 	// eslint-disable-next-line no-empty-pattern
diff --git a/packages/migrate/migrations/self-closing-tags/index.js b/packages/migrate/migrations/self-closing-tags/index.js
index 1c11ea56c448..673a26eb38a8 100644
--- a/packages/migrate/migrations/self-closing-tags/index.js
+++ b/packages/migrate/migrations/self-closing-tags/index.js
@@ -50,7 +50,7 @@ export async function migrate() {
 /** @param {string} name */
 async function import_from_cwd(name) {
 	const cwd = pathToFileURL(process.cwd()).href;
-	const url = await resolve(name, cwd + '/x.js');
+	const url = resolve(name, cwd + '/x.js');
 
 	return import(url);
 }
diff --git a/packages/package/src/index.js b/packages/package/src/index.js
index 6d7450182643..a6cbda297cbb 100644
--- a/packages/package/src/index.js
+++ b/packages/package/src/index.js
@@ -80,7 +80,7 @@ export async function watch(options) {
 	const watcher = chokidar.watch(input, { ignoreInitial: true });
 	const ready = new Promise((resolve) => watcher.on('ready', resolve));
 
-	watcher.on('all', async (type, filepath) => {
+	watcher.on('all', (type, filepath) => {
 		const file = analyze(path.relative(input, filepath), extensions);
 
 		pending.push({ file, type });
diff --git a/packages/package/test/index.js b/packages/package/test/index.js
index 73667f593266..d4bec434d114 100644
--- a/packages/package/test/index.js
+++ b/packages/package/test/index.js
@@ -227,7 +227,7 @@ if (!process.env.CI) {
 			await settled();
 			compare('post-error.svelte');
 		} finally {
-			watcher.close();
+			await watcher.close();
 
 			remove('src/lib/Test.svelte');
 			remove('src/lib/a.js');