Developer builds Mermaid diagram editor, pivots to solving documentation drift

A developer built MermaidCreator, a Mermaid diagram editor featuring a visual canvas, code editor, and AI-powered diagram generation from prompts or whiteboard photos, using Next.js, Supabase, Stripe, and Claude. The core technical lesson was maintaining a single source of truth in the app's store, where visual edits, code edits, and previews stay in sync to avoid bugs. After completing the editor, the developer identified a deeper problem: architecture diagrams become outdated within weeks as codebases evolve, rendering them unreliable. To address this, the app was extended to index docs, Mermaid blocks, API routes, and dependencies from GitHub, Notion, Confluence, and Google Docs, flagging changes that affect existing diagrams for human review. Accepted fixes can be automatically pushed back as GitHub pull requests, though the developer remains uncertain whether the project will become a commercial product.