Backend Development Engineer (Card)

Duties:

1. Card payment system architecture design Responsible for the architecture design and iteration of the credit card/debit card payment core system, covering the full life cycle management of card opening, binding, activation, and cancellation, as well as the development of core modules such as payment transaction authorization, clearing and settlement, and reconciliation.

4. Risk prevention and compliance design Design an anti-fraud rule engine and transaction risk assessment model, integrate real-time risk control systems (such as device fingerprints, transaction behavior analysis), and ensure compliance with the PCI-DSS data security standard and various anti-money laundering (AML), KYC compliance requirements.

5. Payment product feature landing Collaborate with product teams to implement credit card installment payments, pre-authorization, quick payments, and contactless payments, etc. Innovative functions to support multi-terminal (App/Web/PC/ Smart devices) payment scene compatibility development.

6. Data security and audit system Establish a sensitive data encryption mechanism (such as PAN code Tokenization, CVV2 masking processing), improve the transaction log audit system, support the full process tracking of the payment chain, abnormal transaction monitoring and risk early warning.

7. Cross-team collaboration and technical optimization Work closely with risk control, finance, product, and testing teams to drive payment strategy implementation; continuously optimize payment routing algorithm, settlement process, and system disaster recovery solution to enhance system scalability.

Skill requirements

1. Core technology stack

A. Programming language and framework

 Proficient in Java development, familiar with Spring Boot/Spring Cloud frameworks, and with the ability to design independent architectures for payment core modules.

 Familiar with payment industry protocols: PCI-DSS, 3DS 2.0, and familiar with Open Payment API (such as VISA API) integration experience.

B. Data security and encryption

 Master the basics of cryptography (AES encryption, RSA signature, hash algorithm), familiar with TLS/SSL certificate management and HTTPS secure communication configuration.

 Understand Tokenization, data masking, sensitive data isolation, etc. technologies, and have PCI-DSS compliant system design experience.

2. System architecture capability

C. Distributed system design

 Familiar with distributed transaction processing (TCC/SAGA mode), distributed locks (Redis/ZooKeeper), load balancing (Nginx/LVS), and familiar with Kafka/RabbitMQ to achieve asynchronous decoupling.

 Have microservices architecture experience, understand API gateway (Spring Cloud Gateway/Kong) authentication design and service-to-service invocation circuit breaker and rate limiting strategy.

D. Payment system special ability

 Understand the core credit card payment process (authorization, capture, settlement, refund), familiar with the interchange logic between acquirers and issuers, and understand the design of the clearing and settlement reconciliation system.

• Master transaction flow water division, cold and hot data separation, read and write separation, etc. database optimization solutions, familiar

MySQL/PostgreSQL/Redis/MongoDB hybrid storage architecture.

3. Safety compliance and industry standards

E. Compliance design

 In-depth understanding of the PCI-DSS data security standard, able to lead the completion of SAQ self-assessment questionnaire, annual compliance audit cooperation and system rectification.

• Familiar with the payment supervision requirements of various countries, and realize the systematization of KYC/AML processes.

F. Standardized output

• Have the ability to write payment interface documents, transaction risk strategy documents, and compliance technical solutions, and be able to output standardized materials such as the《Payment System Security Specification》《Card Payment Business Technical Manual》

4. Tools and operations capability

• Cloud-native: Familiar with cloud platforms (AWS/Azure/ Alibaba Cloud) related services (such as elastic computing, storage, load balancing), with containerized deployment (Docker/K8s) and CI/CD pipeline setup experience.

 Monitoring and maintenance: Proficient in using Prometheus+Grafana, ELK for transaction performance monitoring and log analysis, with practical experience in payment system fault diagnosis and disaster recovery switching.

5. Bonus

 Familiar with the Open Banking API standard or digital wallet (such as Apple Pay/Google Pay) technology integration;

• Hold PCI-ISA security certification, CISP/CISSP information security certification or financial industry technical qualification certificate; have cross-border payment, multi-currency settlement, exchange rate conversion system design experience.

6. Soft skills

• Full process leadership: Able to independently responsible for the payment project from requirement analysis, technical solution design to online maintenance of the full life cycle management, balancing business requirements and technical implementation costs.

• Cross-domain collaboration: skilled in communicating with non-technical teams, transforming complex technical solutions into business-relevant solutions that can be implemented quickly, and driving rapid iterations of payment products.