01Overview
About the company
Sign3 is an AI-first customer intelligence platform powering fraud prevention, risk scoring, and smarter onboarding decisions for leading FinTechs, banks, and digital businesses. Our flagship SDK and APIs analyze device, behavioral, and digital footprint signals to help clients detect synthetic identities, money mule accounts, and other fraud vectors in real time. We work with top-tier players across credit cards, lending, gaming, and neo-banking, helping them unlock trusted growth at scale. Our systems process millions of risk events per day, with millisecond-level performance and precision. At Sign3, you'll get to build in a rapid-paced, impact-focused setting alongside a lean, high-ownership team.
Role Overview
You will be working on the security of the Sign3 mobile SDKs Android primarily, with iOS exposure over time. Your focus is to build the anti-tampering, anti-hooking, anti-debugging, and integrity primitives that ship inside our SDKs to millions of end-user devices, and to help us stay ahead of the attackers who actively try to bypass them in production.
What You'll Do
Implement and ship detection modules in Kotlin and native C/C++ anti-Frida, anti-Xposed/LSPosed, anti-Magisk/Zygisk, anti-debugging, anti-emulator, repackaging and integrity checks, and hardware-backed attestation flows.
Help build and maintain our adversary-simulation test suite Frida scripts, custom Xposed modules, repackaged APKs and keep it running against every SDK release in CI.
Reproduce customer-reported bypasses on rooted devices; triage with senior engineers, fix, and add a regression test.
Contribute to threat modeling and security architecture reviews for recent SDK features and signals. Partner with the risk/ML team so detections produce signals that hold up server-side.
Do post-deployment signal analysis using internal tooling (Athena, dashboards); collaborate with backend engineers on improving detection logic and tuning loops.
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