Job responsibilities 1. Responsible for the design, development, maintenance and optimization of communication applications and services based on FreeSwitch for the call center. 2. Understand the business, identify the needs, work closely with the team, complete the project and iterative delivery, ensure the quality and schedule. Job qualification 1. 3 ~ 5 years of Java research and development experience, participated in large-scale projects, bachelor degree or above. 2. Java has a solid foundation, excellent coding ability and good development habits, and has the pursuit of technology. 3. Proficient in the mainstream of the open source framework and middleware technology, such as SpringBoot/SpringCloud MyBatis/Redis/MQ, understands the core ideas and principles. 4. Familiar with database technology, such as MySQL, and understand distributed database and big data related technologies. 5. Understand the communication protocols (such as SIP, RTP, RTCP, and HTTP), be familiar with the FreeSwitch architecture and functional modules, and have secondary development experience of FreeSwitch is preferred. 6. Proactive, with good team spirit and communication skills, able to collaborate effectively with other team members.