Developer A

// custom route + session store
await fetch("/api/send-code", { body: phone });
req.session.otp = generateCode();

Developer B

// third-party SDK, different flow
await supabase.auth.signInWithOtp({ phone });
// no shared session shape with rest of app

AI agent

// invents a one-off pattern
const token = await verifyPhoneNumber(auth, phone);
localStorage.setItem("otp_token", token);

Developer A

// IndexedDB + manual merge logic
const db = new Dexie("orders");
await db.orders.put(order);
// custom conflict resolver per field

Developer B

// cache-only, no true offline writes
const { data } = useQuery(["orders"], fetchOrders,
  { staleTime: 60_000, retry: 3 });

AI agent

// fragile local persistence
const orders = JSON.parse(
  localStorage.getItem("orders") ?? "[]"
);

Developer A

// fire-and-forget in the request handler
sendInvoiceEmail(orderId).catch(console.error);
// lost if process restarts

Developer B

// separate infra, separate conventions
await invoiceQueue.add("send", { orderId },
  { attempts: 3, backoff: 5000 });

AI agent

// scheduled inside API route
setInterval(async () => {
  await db.query("SELECT * FROM pending_invoices");
}, 30_000);

Developer A

// inline SMTP, HTML string in handler
await transporter.sendMail({
  to: user.email,
  subject: "Invoice",
  html: `<p>Hi ${user.name}...</p>`,
});

Developer B

// vendor SDK + hardcoded template id
await sgMail.send({
  templateId: "d-abc123",
  to: user.email,
});

AI agent

// webhook to unknown endpoint
await fetch(process.env.EMAIL_HOOK, {
  method: "POST",
  body: JSON.stringify({ user, invoice }),
});