Startups using Postgres:
- Instagram (Handling Growth with Postgres: 5 Tips From Instagram)
- Nextdoor (What is the technology behind Nextdoor?) — I work here.
- Uber (Page on dropboxusercontent.com) — Migrating from MySQL to Postgres.
- Disqus (Postgres at Disqus – keynote)
- Reddit (High Scalability – High Scalability – Reddit: Lessons Learned from Mistakes Made Scaling to 1 Billion Pageviews a Month)
- Etsy (PostgreSQL Featured Users)
- Skype (PostgreSQL Featured Users)