Senior Mobile Engineer (Card & Payment)

Who We Are At OKX, we believe that the future will be reshaped by crypto, and ultimately contribute to every individual's freedom. OKX is a leading crypto exchange, and the developer of OKX Wallet, giving millions access to crypto trading and decentralized crypto applications (dApps). OKX 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. OKX is part of OKG, a group that brings the value of Blockchain to users around the world, through our leading products OKX, OKX Wallet, OKLink and more. About the Opportunity Our Card and Payment engineering team builds reliable, intuitive experiences at the intersection of cards, payments, crypto, and global financial infrastructure. We partner closely with product, design, backend, risk, compliance, and business teams to make card and payment products accessible to users around the world. As a Senior Mobile Engineer on the Card and Payment team, your primary responsibility will be to own and improve the global card issuance process. You will work mainly with product and engineering partners in the US, while meeting regularly with teams in Asia to understand requirements and align delivery. We are looking for someone who is highly self-driven, takes real ownership, collaborates well, and is eager to learn the card issuing and payment businesses in depth. What You’ll Be Doing Own the end-to-end global card issuance process—from eligibility and application through card creation, activation, provisioning, and lifecycle servicing—and improve the experience as OKX expands into new markets. Learn the card issuing and payment domains deeply, and translate business, user, payment, and regulatory requirements into sound architecture, clear trade-offs, and executable delivery plans. Own features from discovery through production, with a strong focus on security, reliability, observability, maintainability, documentation, and test coverage. Drive ambiguous, cross-functional initiatives to completion with a high degree of ownership, self-direction, and sound judgment. Collaborate primarily with product and engineering teams in the US, while joining regular discussions with Asia teams to discover, clarify, and align requirements. Build with Swift, Kotlin, or Rust depending on the problem, and actively learn and adopt new languages, platforms, and tools rather than being limited to a single technology stack. Use AI coding tools throughout the development lifecycle—from exploration and implementation to testing, review, and documentation—while maintaining strong engineering judgment and accountability. Build and maintain reusable AI workflows, engineering harnesses, and technical knowledge bases that improve the entire team’s speed and quality. Review code, share context openly, mentor teammates, and make decisions that improve both engineering quality and overall team outcomes. Contribute to hiring, onboarding, and the continuous improvement of team practices. What We Look For In You B.S. or M.S. in Computer Science, or equivalent practical experience. Proven experience shipping and operating production-quality mobile applications, with deep expertise in iOS or Android. Strong proficiency in at least one of Swift, Kotlin, or Rust, with a demonstrated willingness to learn and contribute in unfamiliar languages and technology stacks. Exceptional ownership and self-direction, with the judgment to make pragmatic decisions and drive ambiguous work to completion. Demonstrated, regular use of AI coding tools with measurable impact on delivery speed, code quality, or engineering effectiveness. A team-first mindset: you communicate openly, share know…