Castle alternatives
TL;DR: 12 companies doing similar work to Castle in Real Estate and Construction, ranked by how closely they match what Castle 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 Castle. They are scored on how closely their own description overlaps with Castle's, and all facts shown come from the YC company records — nothing is estimated.
What are the best alternatives to Castle?
| Alternative | What it does | Batch | Team | Status |
|---|---|---|---|---|
| Travo | . | Winter 2026 | 4 | Active |
| Laguna | — | Winter 2020 | 2 | Inactive |
| Spaces Life | — | Winter 2009 | — | Inactive |
| Houm | All-in-one real estate marketplace for Latin America | Winter 2021 | 400 | Active |
| Sakneen | Shopify for Real Estate Developers | Winter 2020 | 9 | Active |
| Riley | MailChimp for SMS | Winter 2017 | 2 | Inactive |
| Ladder | Labor Marketplace for Construction | Summer 2020 | 1 | Acquired |
| Smart Alto | Easiest way to set appointments with real estate leads | Winter 2017 | 8 | Inactive |
| Atmos | The entire homebuilding process, all online | Summer 2020 | 30 | Inactive |
| Zeus | Tech-enabled property manager focused on corporate rentals; Acquired… | Summer 2011 | 200 | Acquired |
| Union Apartment | Furnished Co-living Apartments for International Students, here in… | Winter 2019 | 12 | Inactive |
| Tuxebo | Online marketplace for equipment rental | Summer 2009 | 3 | Inactive |
Is Castle still active?
Castle 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 Castle. They are then ranked on how closely their own description overlaps with Castle's, so the closest matches come first rather than whoever happens to share a tag.