Sip developer - 100% Remote

Key Responsibilities

• Design, develop, configure, and maintain VoIP and SIP-based communication systems using FreeSWITCH and Kamailio.

• Architect scalable, highly available, and fault-tolerant telephony solutions for healthcare and medical applications.

• Develop and customize FreeSWITCH dial plans, call routing logic, SIP profiles, gateways, and media handling.

• Configure and manage Kamailio as a SIP proxy, registrar, load balancer, and routing engine.

• Implement SIP signaling, call routing, session management, and interoperability between FreeSWITCH, Kamailio, and third-party telecom platforms.

• Integrate telephony systems with healthcare applications, contact centers, patient engagement platforms, appointment scheduling systems, and clinical communication workflows, as applicable.

• Troubleshoot SIP signaling, RTP media, call setup failures, audio quality issues, latency, packet loss, and call drops.

• Implement security measures for SIP communications, including authentication, access control, encryption, and protection against unauthorized access.

• Optimize system performance, scalability, availability, and call quality across high-volume communication environments.

• Collaborate with software engineering, infrastructure, networking, and healthcare application teams to deliver end-to-end communication solutions.

• Monitor production environments, analyze logs and call traces, perform root-cause analysis, and resolve complex telephony issues.

• Support system testing, deployment, upgrades, documentation, and ongoing maintenance.

Required Skills and Qualifications

• Strong hands-on experience in FreeSWITCH and Kamailio — mandatory.

• Proven experience in designing and implementing SIP-based VoIP and telephony solutions.

• Strong understanding of SIP, SDP, RTP, SRTP, and related VoIP protocols.

• Experience with SIP routing, dial plans, gateways, call flows, and media handling.

• Experience integrating FreeSWITCH and Kamailio with external applications, APIs, and telecom services.

• Strong troubleshooting skills in SIP signaling, call routing, audio quality, and network connectivity.

• Experience with Linux environments, networking fundamentals, and scripting or programming for telephony automation.

• Experience with high availability, load balancing, scalability, and production-grade telecom systems.

• Previous experience in the medical or healthcare domain is required.