Staff Software Engineer, Mobile Security

As a Staff Mobile Security Engineer at OKX, you will play a key role in identifying and mitigating security vulnerabilities across OKX's mobile applications and platforms. You join the Mobile Security team at the intersection of offensive security, mobile engineering, and platform protection, working closely with development, operations, and compliance teams to ensure security is embedded at every layer of the mobile stack. You bring deep expertise in mobile application security, offensive techniques, and secure coding practices, and you are fluent in AI-assisted development with the discipline to build and maintain your own AI engineering workflows.

What you'll do

• Identify and address security vulnerabilities in mobile code, systems, and networks through manual review, automated tooling, and threat modelling.
• Manage and optimise application security tools, processes, and alerts to maintain a strong security posture.
• Validate and respond to Bug Bounty submissions, triaging findings and coordinating remediation with engineering teams.
• Produce detailed security findings reports and present them to both technical and management audiences, contributing to real-world attack prevention.
• Collaborate with development teams to implement and champion secure coding practices across iOS and Android platforms.
• Apply AI tools to accelerate security research, automate vulnerability detection workflows, and improve the efficiency of threat analysis.
• Work alongside operations and compliance teams to ensure security is a consistent priority across the organisation.
• Participate in incident response and management activities.
• Stay current on the latest offensive security techniques, application security threats, and industry best practices.

What you bring

• 5+ years of experience in mobile application security or offensive security, with hands-on expertise in iOS and/or Android platforms.
• In-depth understanding of security risks, vulnerabilities, and concepts in mobile and web applications.
• Proficiency in code review across Kotlin, Swift, TypeScript, or JavaScript, with a strong grasp of application security threats.
• Ability to create proof-of-concepts to demonstrate vulnerabilities, review patch code for adherence to standards, and collaborate with repository owners on remediation.
• Active use of AI tools in your security engineering workflow, including building AI-leveraged workflows and codifying repeatable agent skills so tools like Claude Code or Codex deliver reliably on real production work.
• Strong analytical and problem-solving abilities with excellent verbal and written communication skills.

Nice to have

• Prior experience developing mobile security SDKs at scale with a daily active user base of over ten million.
• Experience in large-scale business risk control projects, or practical experience in threat intelligence, business risk prevention, and countermeasures against black and grey industries.
• In-depth reverse engineering of major apps from first-tier vendors, or other projects that demonstrate strong reverse engineering capabilities.
• Proficiency in ARM assembly, with the ability to implement deep-level countermeasures at the native and application layers.
• Experience with device fingerprint recognition, including simulating new devices through methods such as flashing, modification, and application cloning.
• Ability to work across multiple mobile platforms simultaneously.

What we offer

• Competitive total compensation package
• Learning and development programs and education subsidy for your growth and development
• Various team building programs and company events
• Wellness and meal allowances
• Comprehensive healthcare schemes for you and your dependants

About OKX

OKX is a leading crypto exchange and developer of OKX Wallet, giving millions access to crypto trading and decentralized applications. OKX is trusted by hundreds of large institutions seeking access to crypto markets and is backed by Proof of Reserves. OKX is part of OKG, a group bringing the value of blockchain to users worldwide through products including OKX, OKX Wallet, and OKLink.