iOS Developer, Sign3

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 fast-paced, impact-focused environment alongside a lean, high-ownership team.

Role Overview :

We are looking for an experienced iOS Developer with strong expertise in iOS technicals to join our engineering team. The ideal candidate will be responsible for designing, developing, optimizing, and maintaining high-performance iOS SDKs that integrate seamlessly with client applications while ensuring security, scalability, and reliability. The ideal candidate will be the one having in-depth knowledge of ios device architecture, internal device related features, ios jailbreaking and debugging tools. Experience with publishing apps to app stores is a plus.

Key Responsibilities

• Design, develop, and maintain scalable, secure, and high-performance iOS SDKs using Swift and Objective-C, focused on device intelligence, risk assessment, and fraud prevention.

• Build reusable and modular SDK components that seamlessly integrate into client applications while ensuring minimal integration effort and maximum reliability.

• Collaborate closely with backend, Android, product, and fraud intelligence teams to deliver advanced fraud detection, device fingerprinting, and mobile security capabilities.

• Optimize SDK performance, memory consumption, battery efficiency, startup time, and compatibility across a wide range of iOS devices and versions.

• Implement secure data handling, encryption, device intelligence collection, anti-tampering, and anti-abuse mechanisms to strengthen fraud prevention capabilities.

• Develop and enhance jailbreak, rootless jailbreak, and runtime integrity detection mechanisms to identify compromised iOS environments.

• Leverage knowledge of the iOS security ecosystem, including Cydia, package managers, and common jailbreak artifacts, to improve SDK resilience against bypass techniques.

• Analyze and mitigate threats arising from app reverse engineering, instrumentation frameworks, and dynamic analysis tools such as Frida, Cycript, and LLDB.

• Design and implement protections against code injection, hooking, runtime manipulation, and tampering to safeguard SDK functionality and sensitive data.

• Drive continuous improvements in SDK stability, scalability, observability, and developer experience, with a strong focus on reliability and ease of integration.

Requirements

• 3+ years of experience in iOS application development.

• Proficiency in Swift and Objective-C.

• Strong understanding of iOS frameworks, app lifecycle, multithreading, memory management, and networking.

• Experience with SDK packaging and distribution methods such as CocoaPods, Swift Package Manager (SPM), and XCFrameworks.

• Knowledge of REST APIs, JSON parsing, and secure communication protocols.

• Understanding of mobile security concepts including device fingerprinting, jailbreak detection, encryption, and fraud prevention techniques.

• Experience with debugging, profiling, and performance optimization tools.

• Experience working on fraud detection, risk intelligence, cybersecurity, FinTech, or authentication products.

• Knowledge of biometric authentication, device intelligence, or behavioral analytics.

• Experience publishing or managing SDK releases for external clients.