Founding Device Fingerprinting Engineer

About the role

Prelude is building the next generation of fraud‑detection technology and needs a founding engineer to own its device fingerprinting platform. You will define the architecture, lead research, ship production systems and eventually build a team around this critical capability.

Key responsibilities

• Design and implement end‑to‑end fingerprinting pipelines, from signal collection in iOS/Android SDKs and server APIs to real‑time feature generation.
• Develop robust device identity mechanisms, including persistent IDs, rooted/emulated device detection, hardware attestation and anti‑spoofing for web and mobile.
• Create network intelligence signals such as IP reputation, proxy/VPN detection, TLS/JA3/JA4 fingerprinting and carrier enrichment.
• Apply machine‑learning techniques—anomaly detection, clustering, supervised classification—to turn raw attributes into high‑fidelity fraud signals.
• Integrate low‑latency features into Prelude’s real‑time scoring engine and continuously research attacker techniques to stay ahead of evasion methods.

Required profile

• 5+ years of experience delivering production‑grade fraud, bot‑mitigation or mobile‑security systems.
• Deep understanding of device fingerprinting, OS‑level attestation (Play Integrity, DeviceCheck, SafetyNet) and network intelligence.
• Adversarial mindset with hands‑on knowledge of emulators, spoofing tools and proxy infrastructures.
• Strong bias for simple, scalable designs that survive active attack pressure.

Required skills

• Go, Rust or Python for backend and data processing.
• Experience with TLS fingerprinting (JA3/JA4), IP enrichment, proxy/VPN classification, AS analysis.
• Machine‑learning expertise: feature engineering, anomaly detection, clustering, classification.
• Familiarity with iOS and Android SDK internals, Play Integrity, SafetyNet, DeviceCheck.
• Knowledge of stream processing (Kafka, SQS) and OLAP stores (ClickHouse, Redshift).

What we offer

• Competitive salary plus BSPCE equity participation.
• Flexible remote policy with subsidised office travel.
• Health insurance, gym membership, Swile meal vouchers and free office snacks.
• Annual off‑site, modern office in Paris and all necessary equipment.