Staff Software Engineer, Mobile Security

United States Digital Space LLC; Hong Kong; On-site; HKD 800,000 - 1,200,000; Full time

Job summary

The company is a leading crypto exchange seeking a Staff Mobile Security Engineer to join the Mobile Security team in Hong Kong. You will identify vulnerabilities across mobile apps and platforms, working at the intersection of offensive security, mobile engineering, and platform protection.

You will leverage AI-assisted development and build scalable security workflows, collaborating with development, operations, and compliance to embed security across the stack.

Qualifications

• 5+ years in mobile application security or offensive security.
• Hands-on expertise in iOS and/or Android.
• Proficient in Kotlin, Swift, TypeScript, or JavaScript.
• Able to create PoCs and review code for security standards.

Responsibilities

• Identify and address security vulnerabilities in mobile code, systems, and networks via manual review, automated tools, and threat modelling.
• Manage and optimise security tools, processes, and alerts.
• Evaluate Bug Bounty submissions and coordinate remediation with engineering.
• Produce security findings reports for technical and management audiences.

Skills

Mobile security

iOS/Android

Code review Kotlin/Swift/TS/JS

Threat modelling

AI-assisted workflows

Tools

AI tools like Claude Code or Codex

Job description

the company will be prioritising applicants who have a current right to work in Hong Kong, and do not require the company's sponsorship of a visa.

Please note that Hong Kong is a group-level service hub, and the company does not carry on a business of operating a virtual asset trading platform in Hong Kong.

Who We Are

At the company, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom.

the company is a leading crypto exchange, and the developer of the company Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). the company is also a trusted brand by hundreds of large institutions seeking access to crypto markets. We are safe and reliable, backed by our Proof of Reserves.

Across our multiple offices globally, we are united by our core principles: We Before Me, Do the Right Thing, and Get Things Done. These shared values drive our culture, shape our processes, and foster a friendly, rewarding, and diverse environment for every OK-er.

the company is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products the company, the company Wallet, OKLink and more.

About The Opportunity

We are looking for a Staff Mobile Security Engineer to join our Mobile Security team, where you will play a key role in identifying and mitigating security vulnerabilities across the company's mobile applications and platforms. This is a high-ownership role at the intersection of offensive security, mobile engineering, and platform protection — you will work closely with development, operations, and compliance teams to ensure security is embedded at every layer of our mobile stack.

You bring deep expertise in mobile application security, offensive techniques, and secure coding practices. You are also fluent in AI-assisted development and bring the discipline to build, maintain, and continuously improve your own AI engineering workflows.

What You'll Be Doing

• 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 We Look For In You

• 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.
• Proficient in code review across Kotlin, Swift, TypeScript, or JavaScript, with a strong grasp of application security threats.
• Able to create proof‑of‑concepts (PoCs) to demonstrate vulnerabilities, review patch code for adherence to standards, and collaborate with repository owners on remediation.
• Actively uses 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-Haves

• Prior experience developing mobile security SDKs at scale — products 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.

Perks & Benefits

Information about perks and benefits will be provided upon interview.