Senior Fullstack Engineer, Java & ReactJS, Zalo

• Contribute to game-related products and features, collaborating with cross-functional teams to deliver engaging user experiences;
• Develop high-volume, low-latency applications, delivering high-availability and performance from an existing system design;
• Proactively provide technical solutions and system architecture for problems that arise during implementation, working through them with the team;
• Develop, maintain, and optimize ongoing backend features, with a focus on performance and correctness under concurrent load;
• Build and extend functional frontend features in React/TypeScript and integrate them with backend APIs.

Backend (primary focus)

• Having solid knowledge and experience in Java, MySQL, NoSQL;
• Experience with in-memory caching (Redis, Memcached, or similar);
• Practical understanding of distributed systems: handling concurrency and race conditions, idempotency, and fault tolerance;
• Experience optimizing for performance: high-concurrency, low-latency, and system/query tuning;
• Able to design technical solutions and system-level architecture for problems encountered during implementation, not just follow a spec.

Frontend (supporting, ~30%)

• Proficient with React and TypeScript — able to build and extend functional UI features end-to-end and integrate them with backend APIs;
• Experience in game development using engines such as Cocos, Unity, or similar is a plus.

Nice to have

• Experience with Spring Boot;
• Experience with a message broker (Kafka or RabbitMQ);
• Experience with gRPC or Thrift

Become a key player in shaping Zalo’s Game Server architecture — taking ownership of high-concurrency, low-latency systems serving millions of active users with ~70% Backend (Java) and ~30% Frontend (ReactJS)

Become a key player in shaping Zalo’s Game Server architecture — taking ownership of high-concurrency, low-latency systems serving millions of active users with ~70% Backend (Java) and ~30% Frontend (ReactJS)