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Deepn

A couples coaching app built by three AI tools in a row. I audited it, cut it down to the code actually in use, and rebuilt it as one clean, organized codebase.

Case studydeepnapp.com
Client
Deepn
My role
Engineer brought in to rescue the codebase
When
June 2026 to present
Status
Ongoing

The problem

Deepn is a growth and communication tool for couples. Its core feature is a set of AI-guided "trigger" exercises: a user describes a situation and gets coaching on how to handle it better.

The product had been built by three AI tools, one after another: first Replit, then Codex, then Claude Code. Each tool added to what the last one left behind. By the time I joined, the repository was large and incoherent, and it was hard to tell which code was even being used.

This is a common place to end up. AI tools are very good at getting a product to a working demo. They are much less good at keeping the structure clean as features pile up, especially when a different tool picks up where another stopped.

What I did

  • Audited the whole repository and stripped it down to the code that was actually in use.
  • Restructured it into a monorepo. The marketing site moved out into Astro, the app became its own package, and the server was cleaned up.
  • Rewrote the database schema with proper relations, then rebuilt most features on top of it.
  • Optimized queries across the app.

The result

The product now has a structure a developer can understand and change safely: a separate marketing site, app and server, on a schema that reflects how the data actually relates.

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