VoIP Software Engineer (Asterisk)

IDT Corporation IDT Corporation is looking for a Middle VoIP Engineer with a focus on Asterisk. The team is building a cloud PBX solution based on Kamailio and Asterisk (net2phone). We expect you to have strong problem-solving skills, be self-motivated, proactive, and responsible. Your daily duties will include implementing PBX features using Asterisk with respect to high availability and scalability. You are not limited to Asterisk; we welcome you to be involved in all parts of a large ecosystem built around Asterisk, Kamailio, RTPEngine, Java, Kafka, MySQL, MongoDB, CDK, and GitHub Actions pipelines. You will work with automated CI/CD processes and get a chance to improve your knowledge of SIP, cloud infrastructure, and networks. Responsibilities - High-Scale Asterisk: Build and maintain cloud PBX features within a large-scale ecosystem (60k+ users) using Asterisk, Kamailio, and RTPEngine. - Advanced Dialplan Development: Design and implement complex telephony logic specifically using Asterisk dialplans in Lua. - Deep Troubleshooting & Bug Fixing: Analyze stack traces and performance bottlenecks to fix bugs in Asterisk source code and contribute to the community. - Protocol & SIP Proxy Management: Manage complex SIP/RTP flows, SDP negotiation, and NAT traversal for resilient and scalable telephony clusters. - System Maintenance & Reliability: Optimize Linux environments, manage PSTN routing/failover, and participate in on-duty rotations to resolve outages.