The boring stack behind Cold Leads

Cold Leads runs on deliberately boring tech.

• Next.js 16 (App Router) on Vercel
• Postgres through Prisma 7 with the pg driver adapter
• Vercel Cron: sending every minute, inbox and verification every 5 minutes, billing once a day
• Stripe for billing, Resend for system email, Firebase for sign-in
• Users' own mailboxes: Gmail and Microsoft 365 over OAuth, or any SMTP + IMAP account

No queue service, no Kubernetes, no microservices. One repo, one database, a handful of cron endpoints.

For a small product the expensive part isn't the servers. It's every moving piece you have to understand when something breaks.

What's the most boring part of your stack that you'd never replace?

For developers: coldleads.app/developers