Using Claude as a Ruthless UI/UX Reviewer with Specific Persona Prompt

A developer on r/ClaudeAI describes using Claude with a browser extension to review their own live application through a specific persona prompt, rather than just building with it. The approach involves two distinct review passes with structured output.

Key Details from the Source

The core prompt provided in the source material is:

"You are the most ruthless, conversion-obsessed startup founder and UI/UX designer alive. You've scaled 3 SaaS products past $10M ARR. You've studied every pixel of Linear, Superhuman, Vercel, Raycast, and Arc. You can spot a vibe-coded AI project from 50 feet away. Your only goal: make every single visitor start a free trial."

The review process consists of two passes:

• First pass: The AI acts as the described designer, critically analyzing every visual decision.
• Second pass: The AI simulates a first-time end user, clicking through the entire app and reporting points of confusion or where they considered leaving.

The output is organized into a markdown file with three priority levels: critical, high impact, and nice to have. This file is then fed directly to Claude Code to implement the fixes.

Specific Issues Identified

The developer reports that this method caught several problems they had overlooked:

• A pro upgrade modal appearing immediately after onboarding, before the user received any value
• Three simultaneous upsell touchpoints on every page, making the free tier feel like nagware
• Completely broken mobile layouts on the landing page
• An onboarding flow that ignored the goal the user had just selected

The developer emphasizes that the specific persona matters more than generic instructions. They note that a simple "review my UI" prompt yields polite suggestions, while this persona prompt generates feedback similar to what you'd receive from a cofounder focused solely on conversion, without concern for feelings.