Looking for a job

Weinan Zhang

@weinanzhang

Senior Java backend engineer focused on payments, distributed systems, and applied AI. Open to remote roles across APAC and worldwide.

China

Message

What I'm looking for

I’m seeking a senior backend engineering role where I can build reliable payment platforms, distributed systems, and cloud-native services using Java and Spring Boot. I prefer remote, documentation-first teams with strong engineering practices, asynchronous collaboration, and reasonable overlap with UTC+8.

Senior Java backend engineer experienced in building international payment platforms, distributed messaging systems, multi-tenant SaaS, and AI-enabled applications.

I have designed and implemented payment services covering UPI/IMPS pay-ins and payouts, merchant and user balances, settlement, provider integrations, reconciliation, risk controls, and reporting. My core stack includes Java 17, Spring Boot, Spring Cloud, Netty, MySQL, Redis, message queues, Docker, Kubernetes, and AWS.

I also independently launched a multi-model AI assistant built with LangChain4j, RAG, function calling, persistent chat memory, and multimodal models. I am a Hutool open-source contributor and work comfortably in written English, technical documentation, code review, and asynchronous collaboration.

I am currently open to remote Senior Java Backend Engineer, Payments Engineer, Distributed Systems Engineer, and Platform Engineer opportunities across APAC and worldwide.

Experience

Work history, roles, and key accomplishments

Java Payment Engineer

Shenzhen Hermes Technology Co., Ltd. (深圳市赫墨斯科技有限公司)

Aug 2024 - Aug 2026 (2 years)

Designed and implemented international payment services covering UPI/IMPS pay-ins and payouts, balances, settlement, provider integrations, reconciliation, risk controls, and reporting using Java and Spring.