YC S09

3 dead or acquired startups from batch S09 with completed research reports.

Every startup playbook in our database, ready to build

Each deep-dive includes a post-mortem, step-by-step rebuild plan, and a technical spec you can paste straight into Claude Code, Cursor, or Lovable.

Acquired

Bump
Bump, Flock, Photoroll (unreleased) => Google Photos

CarWoo

Marketplace
The best way to buy a new car.

RethinkDB

Open Source
The open source database for the realtime web.