diff --git a/frontend/package.json b/frontend/package.json
index fae465855c..ff5ba3bb8b 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -6,6 +6,7 @@
     "node": ">=22.12.0"
   },
   "engineStrict": true,
+  "type": "module",
   "scripts": {
     "preserve": "vite build",
     "serve": "vite preview",
diff --git a/frontend/postcss.config.js b/frontend/postcss.config.js
index 19551ee89e..5138e1e342 100644
--- a/frontend/postcss.config.js
+++ b/frontend/postcss.config.js
@@ -1,4 +1,4 @@
-module.exports = {
+export default {
   plugins: {
     "postcss-import": {},
     "postcss-scrollbar": {},
diff --git a/frontend/prettier.config.js b/frontend/prettier.config.js
index 67a874ea42..1b3499783d 100644
--- a/frontend/prettier.config.js
+++ b/frontend/prettier.config.js
@@ -1,4 +1,4 @@
-module.exports = {
+export default {
   plugins: ["prettier-plugin-tailwindcss"],
   semi: false,
 }
diff --git a/frontend/tailwind.config.js b/frontend/tailwind.config.js
index b17c24d281..72a934882d 100644
--- a/frontend/tailwind.config.js
+++ b/frontend/tailwind.config.js
@@ -1,8 +1,11 @@
 /** @type {import('tailwindcss').Config} */
-module.exports = {
+import styleDictionary from "@digitalservice4germany/style-dictionary/tailwind"
+import plugins from "@digitalservice4germany/angie"
+
+export default {
   content: ["./src/**/*.{html,vue,js,ts}"],
-  presets: [require("@digitalservice4germany/style-dictionary/tailwind")],
-  plugins: [require("@digitalservice4germany/angie")],
+  presets: [styleDictionary],
+  plugins: [plugins],
 
   theme: {
     fontWeight: {
diff --git a/frontend/test/e2e/caselaw/categories/editableLists/relatedDocumentations/small-search.spec.ts b/frontend/test/e2e/caselaw/categories/editableLists/relatedDocumentations/small-search.spec.ts
index 795f10df3d..3f94b089d6 100644
--- a/frontend/test/e2e/caselaw/categories/editableLists/relatedDocumentations/small-search.spec.ts
+++ b/frontend/test/e2e/caselaw/categories/editableLists/relatedDocumentations/small-search.spec.ts
@@ -1,5 +1,5 @@
 import { expect } from "@playwright/test"
-import errorMessages from "@/i18n/errors.json"
+import errorMessages from "@/i18n/errors.json" with { type: "json" }
 import {
   fillActiveCitationInputs,
   fillEnsuingDecisionInputs,
diff --git a/frontend/test/e2e/caselaw/categories/field-of-law.spec.ts b/frontend/test/e2e/caselaw/categories/field-of-law.spec.ts
index f3d5fd4326..0bcd2fa847 100644
--- a/frontend/test/e2e/caselaw/categories/field-of-law.spec.ts
+++ b/frontend/test/e2e/caselaw/categories/field-of-law.spec.ts
@@ -1,6 +1,5 @@
 import { expect } from "@playwright/test"
-import errorMessages from "@/i18n/errors.json"
-
+import errorMessages from "@/i18n/errors.json" with { type: "json" }
 import { navigateToCategories, save } from "~/e2e/caselaw/e2e-utils"
 import { caselawTest as test } from "~/e2e/caselaw/fixtures"
 
diff --git a/frontend/test/e2e/caselaw/documentunit-search.spec.ts b/frontend/test/e2e/caselaw/documentunit-search.spec.ts
index 225f991a3b..ab4392df56 100644
--- a/frontend/test/e2e/caselaw/documentunit-search.spec.ts
+++ b/frontend/test/e2e/caselaw/documentunit-search.spec.ts
@@ -1,6 +1,6 @@
 import { expect } from "@playwright/test"
 import dayjs from "dayjs"
-import errorMessages from "@/i18n/errors.json"
+import errorMessages from "@/i18n/errors.json" with { type: "json" }
 
 import {
   deleteDocumentUnit,
diff --git a/frontend/test/e2e/caselaw/fixtures.ts b/frontend/test/e2e/caselaw/fixtures.ts
index decfb5e921..afdc533e5f 100644
--- a/frontend/test/e2e/caselaw/fixtures.ts
+++ b/frontend/test/e2e/caselaw/fixtures.ts
@@ -1,6 +1,6 @@
 import { Locator, Page, test } from "@playwright/test"
 import dayjs from "dayjs"
-import utc from "dayjs/plugin/utc"
+import utc from "dayjs/plugin/utc.js"
 import DocumentUnit from "../../../src/domain/documentUnit"
 import { navigateToCategories } from "./e2e-utils"
 import { Page as Pagination } from "@/components/Pagination.vue"