I've watched founders burn 6 months and $40,000 on "scalable architecture" for a product that had zero users.

I've also shipped 7 production SaaS products in 14 days each, with real users, real payments, and real infrastructure.

The difference isn't talent. It's decisions.

Here are the overengineering traps I see constantly — and what to do instead.

Trap 1: Separate microservices from day one

You don't have traffic. You don't have a team. You don't have a reason.

A monolith Next.js app handles everything you need until you have 10,000 daily active users and a concrete bottleneck. Split when you have a real, current problem — not a hypothetical future one.

Do this instead: One Next.js 16 app. Server Actions for mutations. API routes only for external webhooks.

Trap 2: Custom auth from scratch

Every week someone rebuilds JWT refresh logic, session management, and OAuth flows.…