How I built a SaaS in a weekend with Claude + Next.js — the honest breakdown

A developer shares an honest account of building a SaaS prototype over a single weekend using Claude and Next.js. While the AI excelled at rapid scaffolding and boilerplate generation, the author emphasizes that the real challenge lies in verifying the logic of the generated code. A critical near-miss occurred when the AI produced a payment webhook handler that acknowledged transactions before persisting them to the database—a subtle but dangerous bug. The author concludes that relying on AI to both generate and validate code is a flawed approach. Instead, they propose a structural shift: using one AI pass to generate code (the 'author'), a second, separate AI pass to aggressively test and break that code (the 'skeptic'), and a human to make the final decision. This workflow highlights that while AI makes typing faster, the core responsibility of ensuring system reliability remains a human-led process.