Senior Engineer - Fiat Payment，Card

As a Senior Engineer on the OKX Card Team, you build the payment infrastructure connecting digital assets to global commerce. Partnering with Visa and Mastercard, you power the OKX crypto card platform, handling the full card lifecycle and payment stack from instant issuance and real-time transaction authorization to settlement, ledger management, and card growth engines.

What you'll do

• Develop and maintain reliable backend microservices in Java for card issuing, authorization pipelines, and settlement clearing
• Utilize Temporal to manage complex, multi-step transaction lifecycles and resilient distributed state machines
• Design and optimize SQL schemas and queries to ensure correctness and speed across high-concurrency transaction ledgers
• Integrate modern AI development tools into your daily workflow to speed up coding, unit testing, and problem-solving
• Deliver features for promotional campaigns, rewards, and card lifecycle management to support user growth

What you bring

• 1–3 years of backend engineering experience with proficiency in Java (Spring Boot) and relational databases via SQL
• Direct experience or solid understanding of distributed workflow tools like Temporal or Cadence
• Strong background in Fintech with a solid grasp of card transaction mechanics (Visa/Mastercard networks, Auth, clearing, and issuing workflows)
• A proactive mindset for using AI development tools such as Copilot and AI assistants to boost output and maintain high code quality
• Self-driven work style, quick learning ability, and genuine excitement about building secure financial products

Nice to have

• Experience working directly with Card Issuing processors or Payment Service Providers (PSPs)
• A broad understanding of Web3 concepts or crypto-to-fiat conversion flows
• Exposure to cloud-native stacks such as Docker, Kubernetes, AWS, or GCP

About OKX

OKX operates the OKX Card Team, which builds payment infrastructure connecting digital assets to global commerce in partnership with major card networks like Visa and Mastercard.