diff --git a/app/env.server.ts b/app/env.server.ts
index e777723a..d20c370b 100644
--- a/app/env.server.ts
+++ b/app/env.server.ts
@@ -12,7 +12,7 @@ let env: ServerEnv
  * Initializes and parses given environment variables using zod
  * @returns Initialized env vars
  */
-export function initEnv() {
+function initEnv() {
 	// biome-ignore lint/nursery/noProcessEnv: This should be the only place to use process.env directly
 	const envData = envSchema.safeParse(process.env)
 
diff --git a/app/localization/i18n.ts b/app/localization/i18n.ts
index ba43ac74..e42f3300 100644
--- a/app/localization/i18n.ts
+++ b/app/localization/i18n.ts
@@ -1,3 +1,4 @@
+import type { InitOptions } from "i18next"
 import { supportedLanguages } from "./resource"
 
 export default {
@@ -8,4 +9,4 @@ export default {
 	fallbackLng: "en",
 	// The default namespace of i18next is "translation", but you can customize it here
 	defaultNS: "common",
-}
+} satisfies Omit<InitOptions, "react" | "detection">
diff --git a/app/localization/resource.ts b/app/localization/resource.ts
index 539801c7..39301aee 100644
--- a/app/localization/resource.ts
+++ b/app/localization/resource.ts
@@ -19,3 +19,12 @@ export const resources: Record<Language, Resource> = {
 		common: bosnian,
 	},
 }
+
+declare module "i18next" {
+	export interface CustomTypeOptions {
+		defaultNS: "common"
+		fallbackNS: "common"
+		// custom resources type
+		resources: Resource
+	}
+}
diff --git a/app/root.tsx b/app/root.tsx
index 12a011b3..0d50a40c 100644
--- a/app/root.tsx
+++ b/app/root.tsx
@@ -55,8 +55,24 @@ export const Layout = ({ children }: { children: React.ReactNode }) => {
 export const ErrorBoundary = () => {
 	const error = useRouteError()
 	const { t } = useTranslation()
-
-	const errorStatusCode = isRouteErrorResponse(error) ? error.status : "500"
+	// Constrain the generic type so we don't provide a non-existent key
+	const statusCode = () => {
+		if (!isRouteErrorResponse(error)) {
+			return "500"
+		}
+		// Supported error code messages
+		switch (error.status) {
+			case 200:
+				return "200"
+			case 403:
+				return "403"
+			case 404:
+				return "404"
+			default:
+				return "500"
+		}
+	}
+	const errorStatusCode = statusCode()
 
 	return (
 		<div className="placeholder-index relative h-full min-h-screen w-screen flex items-center bg-gradient-to-b from-gray-50 to-gray-100 dark:from-blue-950 dark:to-blue-900 justify-center dark:bg-white sm:pb-16 sm:pt-8">
diff --git a/app/utils/dates.test.ts b/app/utils/dates.test.ts
deleted file mode 100644
index 1f0a0b49..00000000
--- a/app/utils/dates.test.ts
+++ /dev/null
@@ -1,57 +0,0 @@
-import { convertDateToUserTz, convertTz } from "app/utils/dates"
-
-describe("convertTz Test suite", () => {
-	it("should convert date to user tz if there is a difference (1h)", () => {
-		const date = new Date()
-		const serverTz = "Europe/London"
-		const convertedServerDate = convertTz(date, serverTz)
-		const userTz = "Europe/Berlin"
-		const convertedClientDate = convertTz(date, userTz)
-		const differenceInMinutes = Math.round(
-			Math.abs(convertedClientDate.getTime() - convertedServerDate.getTime()) / 60000
-		)
-		expect(differenceInMinutes).toBe(60)
-	})
-
-	it("should stay the same if no difference", () => {
-		const date = new Date()
-		const serverTz = "Europe/London"
-		const convertedServerDate = convertTz(date, serverTz)
-		const userTz = "Europe/London"
-		const convertedClientDate = convertTz(date, userTz)
-		const differenceInMinutes = Math.round(
-			Math.abs(convertedClientDate.getTime() - convertedServerDate.getTime()) / 60000
-		)
-		expect(differenceInMinutes).toBe(0)
-	})
-})
-
-describe("convertDateToUserTz Test suite", () => {
-	it("should convert date to user tz if there is a difference", () => {
-		const request = new Request("http://localhost:3000", {
-			headers: {
-				"CH-time-zone": "Europe/London",
-			},
-			method: "GET",
-		})
-		const date = new Date()
-		const serverDate = convertTz(date, "Europe/Berlin")
-		const clientDate = convertDateToUserTz(date, request)
-		const differenceInMinutes = Math.round(Math.abs(clientDate.getTime() - serverDate.getTime()) / 60000)
-		expect(differenceInMinutes).toBe(60)
-	})
-
-	it("should convert date to user tz if there is a difference", () => {
-		const request = new Request("http://localhost:3000", {
-			headers: {
-				"CH-time-zone": "Europe/London",
-			},
-			method: "GET",
-		})
-		const date = new Date()
-		const serverDate = convertTz(date, "Europe/London")
-		const clientDate = convertDateToUserTz(date, request)
-		const differenceInMinutes = Math.round(Math.abs(clientDate.getTime() - serverDate.getTime()) / 60000)
-		expect(differenceInMinutes).toBe(0)
-	})
-})
diff --git a/app/utils/dates.ts b/app/utils/dates.ts
index e8905772..2a319df3 100644
--- a/app/utils/dates.ts
+++ b/app/utils/dates.ts
@@ -1,6 +1,6 @@
 import { getTimeZone } from "../services/client-hints"
 
-export function convertTz(date: string | Date, tzString: string) {
+function convertTz(date: string | Date, tzString: string) {
 	const dateToConvert = typeof date === "string" ? new Date(date) : date
 	// Convert to the target timezone
 	const convertedDate = new Date(dateToConvert.toLocaleString("en-US", { timeZone: tzString }))