How much funding has Castle raised?

Castle has raised $11.6M in total funding, most recently a Series A round.

Who are Castle's investors?

Castle's investors include Y Combinator Continuity Fund, Index Ventures, F-Prime Capital, Freestyle Capital, Revolution Growth.

Where is Castle headquartered?

Castle is headquartered in San Francisco, California, United States.

What industry is Castle in?

Castle operates in Cybersecurity, SaaS.

Castle

Stop bots and account abuse in minutes

San Francisco, United States · Founded 2015 · $11.6M raised

Cybersecurity

SaaS

Headquarters: San Francisco, California
Employees: 11–50
Founded: 2015
Business Model: B2B

Total Funding: $11.6M
Last Round: $9.2M Series AFeb 2019
Rounds: 3

About

Castle provides dual-layer fraud defense that stops bots and account abuse in minutes, combining edge deployment (native Cloudflare integration or a custom edge stack) with an in-app SDK that tracks sessions, devices, and behavior. The platform analyzes every request for credential stuffing and scripted abuse before it reaches a customer's backend, while surfacing fake signups, account takeovers, and multi-accounting in real time via device fingerprinting, AI risk scoring, and a real-time rules engine. Founded in 2015 by Johan Brissmyr and Sebastian Wallin, Castle is based in San Francisco.

Summary

Castle is a Cybersecurity company based in San Francisco, United States, founded in 2015. It has raised $11.6M in total across 3 rounds, most recently a $9.2M Series A round in Feb 2019. Investors include Y Combinator Continuity Fund, Index Ventures and F-Prime Capital.