Bot detection is broken. Attackers have moved far beyond basic bot scripts—they’re leveraging AI, residential proxies, and sophisticated hybrid automation that easily defeats traditional detection methods. Yet many vendors still treat bot detection as a simple feature, relying on outdated techniques that no longer work. Security systems must evolve to match these advances, or they'll quickly become obsolete.
That’s why I’m excited to share that Antoine Vastel is joining Castle as our new Head of Research. If you’ve worked in bot detection, you already know his name—Antoine’s been at the forefront of this space for over a decade, building some of the most effective defenses against AI-powered threats. He’s spent his career exposing how attackers adapt, pioneering detection techniques that security teams across the industry rely on. Now, he’s bringing that expertise to Castle and our customers.
Why Castle?
Most vendors still rely on basic user agent checks or JavaScript object inspections, but attackers aren’t playing by those rules anymore. That’s why Antoine chose Castle. We’re the only solution that truly merges edge-based bot detection with in-app fraud prevention—something no other vendor has been able to pull off at this level. Attackers don’t just operate at the network layer or within an application—they move across both, and Castle ensures they can’t hide in the gaps.
Here’s what Antoine had to say about joining Castle:
“Castle understands what most security vendors don’t—attackers don’t play by the rules, and defenses need to evolve just as fast. I’ve spent years studying how fraudsters evade detection, but Castle is the first platform I’ve seen that truly integrates edge-based bot mitigation with deep in-app fraud analytics. It’s the most sophisticated approach in the industry, and I’m excited to help take it even further. And what’s even more exciting is what’s coming next—Castle is building an AI-powered product offering that will redefine fraud prevention as we know it.”
Antoine’s impact on bot detection
Antoine has been one of the most influential figures in bot detection research. At DataDome, he built the company’s research arm and led the development of fingerprinting and behavioral analysis models that now serve as the foundation for modern bot defenses. His open-source contributions exposed critical weaknesses in browser fingerprinting, forcing fraudsters to evolve their tactics. His work in AI-resistant detection and low-and-slow credential stuffing prevention has influenced how enterprises protect billions of user interactions daily.
What’s next?
Castle has always been about pushing the limits of what’s possible in fraud prevention. Antoine joining us is a big step toward making sure we stay ahead of an industry that’s just now realizing how hard this problem really is. And we’re not stopping here;
In 2025, we’re launching an AI-powered bot and fraud prevention platform that’s going to push the limits of what’s possible.
Join us
To support this growth, we’ll be hiring aggressively throughout 2025. If you’re passionate about security, AI, and solving problems that most vendors aren’t even thinking about yet, now’s the time to join us.
If you’re still relying on outdated bot mitigation, it’s time to rethink your approach. Let’s go build something better.
Johan Brissmyr
CEO & Co-founder
Castle
