Resurrecting MeCell Maps with Claude Code
Last year I wrote about putting MeCell in the public domain and closing that chapter. The illustration was preserved, but the interactive Google Maps-style website had been dead for years. Symfony 3.2 end-of-life. PHP 5.5.9. Hardcoded credentials. A full LAMP stack required to run what was essentially a static visualization.
I assumed it was gone.
Then, one evening with Claude Code, it wasn’t.
What happened
I pointed Claude Code at the old repository and asked it to think through a refactoring plan. What followed was genuinely surprising: 44 commits, a complete architecture migration from a PHP/MySQL backend to a modern static-first stack, 276 tests written, and a working prototype deployed to mecellmaps.mxschons.com.
The original codebase was roughly 65,000 lines of legacy PHP and Twig templates. The new version is around 12,700 lines of vanilla JavaScript with OpenLayers 8, offline PWA support, and accessibility features the 2016 version never had.
I gave maybe 10-15 prompts total. The rest was autonomous execution against a plan it generated.
Why this matters to me
I spent over 1,000 hours creating that cell map during medical school. Watching it become inaccessible felt like losing something. A month-long refactor was never going to happen alongside actual work.
One evening did happen.
There’s something poetic about working on AI risk mitigation by day, then watching an AI agent resurrect a passion project by night. The capability cuts both ways, and I think we need to hold both truths: this technology is powerful, it can do beautiful things, and that’s exactly why getting it right matters.
Try it
Explore the interactive cell map at mecellmaps.mxschons.com. All 537 structures, 10 metabolic pathways, Wikipedia integration, and a guided tour.
The illustration itself remains in the public domain on Wikimedia Commons.
Appendix: Technical Migration
| 2016 | 2025 | |
|---|---|---|
| Backend | Symfony 3.2 + PHP 5.5.9 | None (static-first) |
| Database | MySQL 5.7 + Doctrine ORM | Static JSON files |
| Frontend | jQuery + Bootstrap 3 + OpenLayers 3 | Vanilla ES2022+ + OpenLayers 8 |
| Build | Assetic + Bower | Vite 5 |
| Tests | None | 276 (Vitest + Playwright) |
Claude Code: 44 commits, 1,388,451 lines added, 3,682 removed.