Zalopay, Senior Software Engineer

The
- **Core Payment team** is the heart of ZaloPay, serves as the central component of ZaloPay, one of leading e-wallet platforms in Vietnam. Our primary responsibility is to handle various transaction processes and manage the fund flows, encompassing activities such as top-ups, withdrawals, transfers, and payments. With a focus on meeting stringent technical requirements, our system ensures a seamless and secure payment experience by delivering exceptional performance in terms of throughput, latency, availability, and scalability.
- Additionally, our team extends support to critical financial domains, actively contributing to the development of high-performance services and financial products dedicated to accounting, finance, and business operations. Through our efforts, ZaloPay can provide instant money transfers, expedited operations, and top-level security measures. As a result, we play a crucial role in ZaloPay's commitment to advancing a cashless society, delivering a wide range of services and enticing offers to our users.**Responsibilities (You will)**
- Design, build, and maintain large-scale services, data pipelines, tooling, and systems to ensure a direct business impact in ZaloPay’s mission-critical business domains including Product, Merchant, Accounting, Finance, and Business Operations.
- Write clean, efficient, and well-documented code using best practices.
- Debug and resolve complex issues that may arise in the system and address performance bottlenecks.
- Collaborate with cross-functional teams, including product managers, designers, and other engineers to define requirements and deliver high-quality solutions.
- Keep up-to-date with the latest technologies and trends in the industry and identify opportunities for improvement.
- Work in an Agile & collaborative environment involving different stakeholders.
- Able to work in a high-pressure environment.

**Yêu cầu**:

- Have implemented and delivered distributed systems on a large scale.
- Have experience with distributed transaction algorithms such as TCC, SAGA, Two-Phase Commit.
- Extensive experience working with databases, including SQL and NoSQL systems.
- In-depth knowledge of database design principles and performance optimization techniques.
- Strong understanding of consensus algorithms, such as Paxos, Raft, or Practical Byzantine Fault Tolerance (PBFT).
- Have experience with distributed caching such as Redis, distributed locking such as ZooKeeper, and distributed event streaming platforms such as Kafka.
- Write high-quality & maintainable codes. We work mostly in Java.
- Have experience in operating and maintaining a large scale system.
- Have experience in tracing system problems.

**The following skills would be nice to have**
- Experience with Java technologies: Spring Boot, Reactive Programming, Concurrent/Parallel Programming, Messaging Frameworks,...
- Experience with big-data technologies such as Apache Kafka, Apache Spark, Presto, Apache Flink, and OLAP.
- Experience in optimizing JVM.
- Experience with financial-related platforms/products is a plus.
- Knowing how to work with K8S or cloud services, e.g GCP, AWS... is a big plus.

**Our selling points**:

- At ZaloPay, we develop the CORE transaction processing in-house. We have created a system that can effectively serve the Vietnamese market on a daily basis as well as during high-volume periods such as Tet, holiday, promotion campaign... Our system is scalable, highly available, secure, and can handle a large volume of transactions efficiently while ensuring accuracy and the safety of funds.
- Payment Engine is a high-performing team with team morale high and everyone is happy. We are promoting a positive, innovative, and productive work environment, fostering cross-functional collaboration, and promoting continuous learning and improvement.