Senior / Staff Software Engineer, Mobile — Core (Account & Risk)

Own the account backbone of a CeFi platform trusted by millions — login, registration, account security, MFA, Passkey — where a single security regression is measured in real user funds. The more senior you are, the more you set the technical direction others build on.

• Own account-system subsystems end-to-end — authentication, MFA, Passkey/WebAuthn, session & device trust, account registration and recovery — including architecture, tradeoffs, and long-term evolution.
• Design flows that are secure and low-friction at millions-of-DAU scale — the hardest tradeoff in this space.
• Partner with risk & security teams to turn threat models into shipped mobile defenses.
• Build our AI-native engineering practice — design automated development workflows and harness systems (agents, evals, guardrails, CI integration) that let AI do real engineering work, while safeguarding delivery quality and efficiency.
• Raise the bar through design and code review, and by making the engineers around you better.
• At the Staff level: set technical direction beyond your own subsystem and drive cross-team, cross-timezone decisions that shape the account platform.

• Deep, hands-on experience building native iOS and/or Android — you understand the platform, not just a framework on top of it.
• Experience with a cross-platform / shared business-logic layer. We build ours in Rust + UniFFI; direct Rust-on-mobile experience is a strong plus, but experience with any shared-logic approach — KMP, Flutter, or React Native — transfers well and is valued.
• Fluent in at least one of: Swift / Kotlin / Rust / Objective-C / Java / JavaScript, with strong CS fundamentals.
• Architecture experience with large-scale mobile apps — you've applied maintainable design patterns and own solutions from requirements through to production.
• Hands-on with mobile authentication & security — OAuth/OIDC, MFA, secure storage (Keychain/Keystore), biometrics. Direct experience with Passkey / WebAuthn / FIDO2 is a strong advantage — it's live in our stack and central to what you'll work on.
• Solid grasp of threat modeling and the mobile attack surface.
• You apply AI deeply in your own engineering — not just code generation. You've built, or are driven to build, automated development workflows and harnesses that make delivery both faster and more reliable. Solid grasp of LLM fundamentals, prompt engineering, RAG, and agent concepts, with hands-on experience taking an AI pipeline from scratch to shipped.
• Comfortable with ambiguity and high scale — you've debugged problems that only appear under real production load.
• Signals we value: you naturally raise the standard of teams you join, mentor without being asked, and can grow into a technical anchor for the group.

• Fraud / risk, cryptography, or regulated-industry (fintech) experience.
• Experience with mini-program or dynamic/hot-update frameworks.
• Crypto trading / Web3 experience.

• Competitive total compensation package
• L&D programs and Education subsidy for employees' growth and development
• Various team building programs and company events
• Wellness and meal allowances
• Comprehensive healthcare schemes for employees and dependants
• More that we love to tell you along the process!

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

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

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