Castle

castle.io

information technology & services

castle.io

San Francisco, California, United States

11-50 employees

4000000 revenue

LinkedIn Profile

About Castle

cyber security, developer apis, fraud detection, security, development platforms, enterprise software, internet, information technology, software, software development, custom security flows, transaction abuse, request velocity monitoring, velocity query optimization, webhook integration, bot detection, pattern analysis, trusted device lists, information technology and services, device fingerprinting

Castle's Tech Stack

AI/ML

Decision Makers at Castle

5 contacts

Sebastian Wallin

Co-founder & CTO

s***@castle.io Sign up to view

Antoine Vastel

Head of Research

a***@castle.io Sign up to view

Adam Zima

Head of Product & Engineering

a***@castle.io Sign up to view

Stephen Song

CEO & Co-Founder

s***@castle.link Sign up to view

Johan Brissmyr

CEO & Co-founder

j***@castle.io Sign up to view

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38 technologies detected · 5 decision makers · Emails available

Sales Outreach Angle

AWS infrastructure signals engineering sophistication. This company likely evaluates cloud cost management, security tooling, observability, and developer productivity solutions.

Castle's Position in the StackWho Database

• Castle is 1 of 194,140 information technology & services companies tracked in StackWho.
• 193,618 information technology & services companies in our database have verified decision-maker emails (100% of the cohort).
• 53,147 companies in California are in the StackWho database.
• 74,148 information technology & services companies are in the 11-50 employee range (same size as Castle).

Technology detection from public web signals. Decision-maker contacts compiled from LinkedIn public profiles, company filings, and verified outbound testing. Methodology & sources · Updated August 2026.

Frequently Asked Questions

What technology does Castle use?

Castle uses Route 53, Sendgrid, Gmail, Pardot, Google Apps, Microsoft Office 365, and 32 more technologies. This data is sourced from StackWho's technology detection engine.

How do I contact the decision makers at Castle?

StackWho has verified email addresses for 5 decision makers at Castle. Pro members can access direct emails for the CEO, CTO, VP of Engineering, and other key contacts. Use StackWho to reach Castle directly for sales, recruiting, or partnerships.

What industry is Castle in?

Castle operates in the information technology & services industry, headquartered in San Francisco, California, United States. StackWho tracks technology stacks and decision maker contacts for companies across all industries.

Can I export Castle's contact data?

Yes. StackWho Pro members can export decision maker contact data for Castle and similar companies to CSV. Use the export feature to build targeted prospect lists segmented by technology stack, industry, or location.