Launch Day War Room & Triage Guide

What happens when 5,000 visitors land on your site simultaneously on Product Hunt? Database connection pools choke, Vercel hits 10-second timeouts, and Stripe webhooks fall behind. Here are the 60-second emergency fixes for the 5 most common launch disasters.

Launch Panic #1

Database Connection Pool Exhaustion (500 Internal Server Error)

Symptom

App crashes with "FATAL: remaining connection slots are reserved for non-replication superuser connections" or "Max client connections reached".

Root Cause

Serverless functions on Vercel spin up 50 isolated lambdas, each opening its own raw PostgreSQL connection without connection pooling.

60-Second Quick Fix

Switch your DATABASE_URL from direct connection port 5432 to pooled port 6543 (PgBouncer mode in Supabase/Neon).

# Change your DATABASE_URL in Vercel environment variables:
# Direct connection (breaks under traffic):
# postgresql://postgres:[password]@db.xyz.supabase.co:5432/postgres

# Pooled connection (handles 10,000 serverless connections):
DATABASE_URL="postgresql://postgres:[password]@db.xyz.supabase.co:6543/postgres?pgbouncer=true"

Launch Panic #2

Stripe Webhook Storm & Unupgraded Paid Users

Symptom

Customers are charged on Stripe, but their accounts are never upgraded in your database and they complain on Twitter.

Root Cause

Webhook handler failed HMAC signature verification (e.g. read body as req.json()) or threw an unhandled error, causing Stripe to queue retry deliveries.

60-Second Quick Fix

Check Stripe Dashboard > Developers > Webhooks > Failed Events. Verify your endpoint uses raw text buffering and returns a 200 acknowledgment.

// app/api/webhooks/stripe/route.ts
import { NextResponse } from 'next/server';
import Stripe from 'stripe';

const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!);

export async function POST(req: Request) {
  const body = await req.text(); // Raw text preserves HMAC signature!
  const signature = req.headers.get('stripe-signature')!;

  try {
    const event = stripe.webhooks.constructEvent(
      body,
      signature,
      process.env.STRIPE_WEBHOOK_SECRET!
    );

    if (event.type === 'checkout.session.completed') {
      const session = event.data.object as Stripe.Checkout.Session;
      // Upgrade customer in database
    }

    return NextResponse.json({ received: true }, { status: 200 });
  } catch (err: any) {
    return NextResponse.json({ error: err.message }, { status: 400 });
  }
}

Launch Panic #3

Vercel 504 Gateway Timeout on AI Generation Routes

Symptom

Users wait 10 seconds for an AI completion or report, and the page aborts with an HTTP 504 Gateway Timeout error.

Root Cause

Vercel serverless functions on the Hobby tier default to a strict 10-second execution limit. Complex LLM completions easily exceed 10 seconds.

60-Second Quick Fix

Add export const maxDuration = 60 to your Next.js route handler, or stream output using ReadableStream.

// In app/api/generate/route.ts:
// Extend maximum execution duration on Vercel (up to 60s on Pro, 300s on Enterprise):
export const maxDuration = 60;
export const dynamic = 'force-dynamic';

export async function POST(req: Request) {
  // Long-running LLM completion here
}

Launch Panic #4

Transactional Email Quotas Exceeded (Resend / SendGrid)

Symptom

New signups or password reset emails stop sending, and API calls return 429 Too Many Requests or "Daily quota reached".

Root Cause

Default free tiers allow 100 emails/day. A Product Hunt launch with 500 signups hits this wall within 30 minutes.

60-Second Quick Fix

Upgrade your email tier before launch day, or log magic link URLs to server console as an immediate manual fallback.

// Temporary fallback logger if email provider drops
try {
  await resend.emails.send({ ... });
} catch (emailError) {
  console.error("CRITICAL EMAIL FAILURE. Fallback Magic Link:", magicLinkUrl);
  // User can contact support and you can give them their link manually from logs
}

Launch Panic #5

Runaway Token Burn & 429 Provider Rate Limits

Symptom

OpenAI or Anthropic dashboard shows credit balance falling rapidly or returning 429 Too Many Requests.

Root Cause

Scrapers or curious visitors triggering infinite prompts without user authentication or rate limits.

60-Second Quick Fix

Enforce user authentication before allowing LLM completions and configure max_tokens limits on all completion requests.

// Restrict completions to logged-in users only:
const session = await auth();
if (!session?.user?.id) {
  return Response.json({ error: 'Please sign in to generate' }, { status: 401 });
}

// Cap max output tokens on model completion:
const response = await openai.chat.completions.create({
  model: 'gpt-4o',
  max_tokens: 800, // Hard ceiling prevents runaway spend
  messages: [...],
});

Pre-Empt Launch Day Chaos

Catch these bottlenecks before you tweet your link.

Why wait until launch day to find out your connection pool is unconfigured? Run all 108 launch readiness checks with the Founder Pass ($15 one-time) and ship with complete peace of mind.

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