diff --git a/apps/website/src/app/api/draft/route.ts b/apps/website/src/app/api/draft/route.ts
index f2458f8..4eeaa81 100644
--- a/apps/website/src/app/api/draft/route.ts
+++ b/apps/website/src/app/api/draft/route.ts
@@ -1,8 +1,7 @@
 import { draftMode } from "next/headers";
 import { redirect } from "next/navigation";
-import { z } from "zod";
 
-const DRAFT_MODE_SECRET = z.string().parse(process.env.DRAFT_MODE_SECRET);
+const { DRAFT_MODE_SECRET } = process.env;
 
 export const GET = async (request: Request) => {
   const { searchParams } = new URL(request.url);
diff --git a/apps/website/src/app/layout.tsx b/apps/website/src/app/layout.tsx
index 6ee6b22..a8242d7 100644
--- a/apps/website/src/app/layout.tsx
+++ b/apps/website/src/app/layout.tsx
@@ -6,6 +6,7 @@ import { ReactNode } from "react";
 import { DraftModeBanner } from "../components/DraftModeBanner/DraftModeBanner";
 import { Footer } from "../components/Footer/Footer";
 import { Navigation } from "../components/Navigation/Navigation";
+import "../lib/env";
 import { createGenerateMetadata, ogImage } from "../lib/metadata";
 import { getMetadata } from "../lib/queries";
 import "../styles/global.css";
diff --git a/apps/website/src/components/Carousel/Carousel.tsx b/apps/website/src/components/Carousel/Carousel.tsx
index d0ab775..07d3dc7 100644
--- a/apps/website/src/components/Carousel/Carousel.tsx
+++ b/apps/website/src/components/Carousel/Carousel.tsx
@@ -122,7 +122,7 @@ export const Carousel = <Item extends {}>({
             <AnimatePresence initial={false} custom={direction()}>
               <m.div
                 className="absolute h-full w-full bg-background-primary py-16"
-                key={Math.random()}
+                key={selectedItemIndex}
                 variants={variants}
                 initial="enter"
                 animate="center"
diff --git a/apps/website/src/lib/env.ts b/apps/website/src/lib/env.ts
new file mode 100644
index 0000000..a6f62a6
--- /dev/null
+++ b/apps/website/src/lib/env.ts
@@ -0,0 +1,16 @@
+import { z } from "zod";
+
+const envSchema = z.object({
+  DRAFT_MODE_SECRET: z.string().min(1),
+  SANITY_PROJECT_ID: z.string().min(1),
+  SANITY_AUTH_TOKEN: z.string().min(1),
+  NEXT_PUBLIC_VERCEL_ENV: z.enum(["preview", "production"]).optional(),
+});
+
+envSchema.parse(process.env);
+
+declare global {
+  namespace NodeJS {
+    interface ProcessEnv extends z.infer<typeof envSchema> {}
+  }
+}
diff --git a/apps/website/src/lib/sanity.ts b/apps/website/src/lib/sanity.ts
index d7c9e16..1556813 100644
--- a/apps/website/src/lib/sanity.ts
+++ b/apps/website/src/lib/sanity.ts
@@ -3,8 +3,8 @@ import "server-only";
 import { draftMode } from "next/headers";
 import { z } from "zod";
 
-const SANITY_PROJECT_ID = z.string().parse(process.env.SANITY_PROJECT_ID);
-const SANITY_AUTH_TOKEN = z.string().parse(process.env.SANITY_AUTH_TOKEN);
+const { SANITY_PROJECT_ID, SANITY_AUTH_TOKEN } = process.env;
+
 const DATASET = "production";
 const API_Version = "2023-10-12";
 
diff --git a/apps/website/src/lib/tracking.ts b/apps/website/src/lib/tracking.ts
index 3d06cd7..ee95e21 100644
--- a/apps/website/src/lib/tracking.ts
+++ b/apps/website/src/lib/tracking.ts
@@ -1,3 +1,5 @@
+const { NEXT_PUBLIC_VERCEL_ENV, NODE_ENV } = process.env;
+
 interface TrackingEvents {
   "Carousel item selected": {
     item: any;
@@ -25,10 +27,10 @@ export const track = <TEventKey extends keyof TrackingEvents>(
     : [event: TEventKey, data: TrackingEvents[TEventKey]]
 ) => {
   const [event, data] = args;
-  if (process.env.NEXT_PUBLIC_VERCEL_ENV === "production") {
+  if (NEXT_PUBLIC_VERCEL_ENV === "production") {
     splitbee.track(event, data);
   }
-  if (process.env.NODE_ENV === "development") {
+  if (NODE_ENV === "development") {
     console.info("Tracking event:", {
       event,
       data,