FathomDB alternatives
TL;DR: 12 companies doing similar work to FathomDB in B2B, ranked by how closely they match what FathomDB actually does — not just by category.
How this list was built: every company here is Y Combinator-backed and shares at least one category with FathomDB. They are scored on how closely their own description overlaps with FathomDB's, and all facts shown come from the YC company records — nothing is estimated.
What are the best alternatives to FathomDB?
| Alternative | What it does | Batch | Team | Status |
|---|---|---|---|---|
| Insoshi | — | Winter 2008 | — | Inactive |
| Fithub | — | Winter 2010 | — | Inactive |
| Cloudant | NoSQL Database-aaS. Acquired by IBM in 2014. Now IBM Cloud Data… | Summer 2008 | 51 | Acquired |
| Citus Data | Real-time. Big data. PostgreSQL | Summer 2011 | 45 | Acquired |
| Ardent | Database sandboxes for Agents | Spring 2026 | 3 | Active |
| Twolabs | RL environments for underexplored domains. | Spring 2026 | 2 | Active |
| primitive | communication for agents | Spring 2026 | 4 | Active |
| Dialogus | voice AI agents that learn how your company actually works | Summer 2026 | 3 | Active |
| PhoneSys | The Phone System for Sales Teams. | Summer 2011 | 4 | Inactive |
| Tapzilla | Woot for iOS apps. | Summer 2010 | 2 | Acquired |
| OneSignal | Engage customers through personalized omni-channel messaging | Summer 2011 | 150 | Active |
| Etleap | Etleap is an ETL solution for creating perfect data pipelines. | Winter 2013 | 11 | Active |
Is FathomDB still active?
FathomDB is no longer listed as active, so anyone still relying on it should plan a migration to one of the alternatives above.
How was this list put together?
Every company here is Y Combinator-backed and shares at least one category with FathomDB. They are then ranked on how closely their own description overlaps with FathomDB's, so the closest matches come first rather than whoever happens to share a tag.