Device Fingerprinting Engineer

Stack

Responsibilities

• ▹Design and improve the fingerprinting system, from signal collection to matching logic
• ▹Propose new approaches to measure fingerprint quality, stability, and long-term effectiveness
• ▹Detect manipulated or inconsistent fingerprints in adversarial browser environments
• ▹Build matching algorithms that remain reliable despite drift, collisions, and partial fingerprints
• ▹Keep the system performant and resilient as browsers and attacker techniques evolve
• ▹Collaborate with JavaScript researchers and detection engineers to design new signals

Requirements

• ▹Proven experience building or operating device fingerprinting systems at real scale
• ▹Hands-on experience with signal collection in real browsers
• ▹Experience dealing with unstable signals, fingerprint collisions, and manipulated environments
• ▹Understanding of tradeoffs between entropy, stability, and collection cost
• ▹Experience designing matching or clustering algorithms under noisy, adversarial conditions

Soft skills

What we offer

• ▹US-level pay

About the company

Castle is a small, profitable team building a real-time trust layer for modern platforms, with fingerprinting as one of its core components.