Castle

Design and maintain robust, scalable detection systems to identify and mitigate bot and fraud activity. Ensure system observability and performance while balancing business trade-offs and minimizing false positives.

You will own the end-to-end fingerprinting system, from browser-based signal collection to server-side matching logic. This involves collaborating with researchers to design new signals and building algorithms that maintain reliability despite adversarial conditions and signal drift.

You will own the end-to-end development and architecture of mobile SDKs for iOS and Android. This includes building reliable signal collection mechanisms, managing build systems, and ensuring SDK performance across diverse device environments.