fix(perf): persist Prisma singleton in production & add timing breakdown

src/app/api/shorten/route.ts

@@ -6,8 +6,10 @@ import { generateUniqueShortCode } from "@/lib/short-code";
 import { generateQRCodeDataUrl } from "@/lib/qr";
 
 export async function POST(req: Request) {
+  const t0 = performance.now();
   try {
     const user = await getCurrentUser();
+    const tAuth = performance.now();
     const body = await req.json();
     const { url, custom_code, password, tags, expires_at, display_on_portal } = body;
 
@@ -62,6 +64,7 @@ export async function POST(req: Request) {
       // Auto-generate using configured default_url_length
       shortCode = await generateUniqueShortCode();
     }
+    const tCodeGen = performance.now();
 
     // Hash password if set
     let hashedPassword: string | null = null;
@@ -111,13 +114,15 @@ export async function POST(req: Request) {
         tags: true,
       },
     });
+    const tDbCreate = performance.now();
 
     // Build absolute short URL
     const appUrl = (process.env.NEXT_PUBLIC_APP_URL || "http://localhost:3000").replace(/\/$/, "");
     const fullShortUrl = `${appUrl}/${shortCode}`;
 
     // Generate QR Code
-    const qrCodeDataUrl = await generateQRCodeDataUrl(fullShortUrl, { size: 280 });
+    const qrCodeDataUrl = await generateQRCodeDataUrl(fullShortUrl, { size: 240 });
+    const tQr = performance.now();
 
     return NextResponse.json({
       success: true,
@@ -133,6 +138,13 @@ export async function POST(req: Request) {
         display_on_portal: createdUrl.displayOnPortal,
         tags: createdUrl.tags.map((t) => t.name),
       },
+      _timings: {
+        auth_ms: Math.round(tAuth - t0),
+        code_gen_ms: Math.round(tCodeGen - tAuth),
+        db_create_ms: Math.round(tDbCreate - tCodeGen),
+        qr_ms: Math.round(tQr - tDbCreate),
+        total_server_ms: Math.round(tQr - t0),
+      },
     });
   } catch (error) {
     console.error("Shorten API error:", error);

src/lib/prisma.ts

@@ -10,4 +10,4 @@ export const prisma =
     log: process.env.NODE_ENV === "development" ? ["warn", "error"] : ["error"],
   });
 
-if (process.env.NODE_ENV !== "production") globalForPrisma.prisma = prisma;
+globalForPrisma.prisma = prisma;