Senior Engineer - Fiat Payment，Card

The role

This person will develop and maintain backend microservices in Java for card issuing, authorization pipelines, and settlement clearing. They will use Temporal to manage transaction lifecycles and optimize SQL schemas for transaction ledgers.

What you will 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 exactness 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.

Required qualifications

• 1–3 years of backend engineering experience proficient 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).
• Proactive in using AI development tools (e.g., Copilot, AI assistants) to boost output and maintain high code quality.
• Highly self-driven, quick learner, and excited to build secure financial products.

Nice to have

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

About the company

The OKX Card Team builds the payment infrastructure connecting digital assets to global commerce. They partner with major card networks like Visa and Mastercard to power the OKX crypto card platform.