Java Backend Developer – Instant Messaging

The ideal candidate will be a qualified Java Backend Developer to join our team, focusing on building and optimizing the backend systems that power our Instant Messaging (IM) platform. You will play a key role in delivering core features such as real-time messaging, user presence, and group communications, ensuring performance and reliability at scale.

Key Responsibilities

• Design and develop backend services to support instant messaging features
• Implement core modules such as message delivery, user presence tracking, and group management
• Ensure system reliability, scalability, and support for high-concurrency environments
• Collaborate with cross-functional teams to deliver high-quality features on time
• Conduct performance tuning, debugging, and production issue resolution

Requirements

• Strong proficiency in Java, with hands-on experience in Spring / Spring Boot, Netty, and related backend frameworks
• Prior experience with instant messaging systems, chat protocols, and push notifications is a strong advantage
• Solid understanding of distributed system design, caching mechanisms, message queues (e.g., Kafka, RabbitMQ), and database performance optimization
• Commitment to clean coding practices, unit testing, and code documentation
• Excellent problem-solving skills and effective communication in cross-functional environments