Senior Mobile Engineer (Card & Payment)

United States Digital Space LLC; San Jose (CA); On-site; USD 150,000 - 230,000; Full time

Job summary

United States Digital Space LLC is seeking a Senior Mobile Engineer for the Card & Payment team in San Jose. You will own the global card issuance lifecycle and work with US and Asia teams to deliver secure, scalable mobile experiences.

Ideal candidates have production mobile app experience, deep iOS or Android expertise, and comfort with Swift, Kotlin, or Rust. You’ll drive architecture decisions, leverage AI coding tools, and mentor teammates in a fast-growing crypto fintech environment.

Qualifications

• Experience shipping production mobile apps (iOS or Android).
• Proficient in Swift, Kotlin, or Rust; willing to learn others.
• Demonstrated ownership, self-direction, and accountability.
• Regular use of AI coding tools with measurable impact.
• Strong communication in English; Mandarin proficiency preferred.

Responsibilities

• Own end-to-end global card issuance workflow from eligibility to lifecycle servicing.
• Translate business and regulatory requirements into architecture and delivery plans.
• Own features from discovery through production with emphasis on security and reliability.
• Collaborate with US product/engineering teams and Asia partners.
• Build with Swift, Kotlin, or Rust and learn new languages as needed.
• Develop reusable AI workflows and engineering knowledge bases.
• Review code, mentor teammates, and drive engineering quality.
• Contribute to hiring and onboarding improvements.

Skills

Mobile app development

iOS/Android

Swift Kotlin Rust

AI coding tools

Ownership & initiative

English Mandarin

Education

B.S./M.S. in Computer Science

Job description

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

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 the company 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 knowledge, support peers, and align technical decisions around the best outcome for the team and product.
• Genuine curiosity about card issuing and payment businesses, plus the ability to communicate technical decisions clearly with partners across the US and Asia. Professional proficiency in English and Mandarin Chinese is required.

Nice to Haves

• Hands-on experience with global card issuance flows, card processing, payments, fintech, crypto, or other high-trust financial products.
• Experience launching products across multiple countries or regulatory environments.
• Knowledge of mobile security, payment authentication, risk controls, or transaction lifecycle design.
• Experience improving mobile architecture, shared components, developer tooling, or engineering productivity at team scal