Custom Software Engineer

Voice Socket Application Developer

We are seeking a highly skilled Voice Socket Application Developer with 5+ experience in Socket Programming (Node.js or Python) and real-time communication systems. The ideal candidate will design, develop, and integrate advanced SIP/VoIP applications, IVR workflows, and custom dial-plans leveraging open-source or commercial telephony platforms such as Asterisk, FreeSWITCH, or Kamailio. This role requires strong problem-solving skills in real-time communication environments and hands-on experience with SIP signaling and media handling.

Roles & Responsibilities

• VoIP & SIP Application Development
• Design, develop, and maintain SIP-based and VoIP applications using Node.js or Python.
• Implement advanced socket communication for call events, signaling, and session control.
• Handle SIP protocols (INVITE, ACK, BYE, REGISTER, OPTIONS, etc.) and ensure reliable signaling flows.
• IVR & Dial-Plan Development
• Build and customize IVR workflows, call routing logic, and voice prompts.
• Create, optimize, and maintain SIP dial-plans and call handling features (transfers, hold, forwarding).
• Integrate IVR flows with backend systems, APIs, and databases.
• Telephony Platform Integration
• Integrate with PBX systems such as Asterisk, FreeSWITCH, or Kamailio/OpenSIPS.
• Connect and configure SIP trunks and carrier interconnects.
• Work with media servers for DTMF handling, RTP streaming, codec management (G.711, G.729, Opus), and NAT traversal.
• Monitoring, Debugging & Optimization
• Analyze and debug SIP messages, RTP streams, and media quality issues.
• Use protocol analysis tools for troubleshooting real-time communications.
• Collaborate with DevOps/Infra teams to deploy, monitor, and scale applications in production.
• Documentation & Collaboration
• Prepare technical documentation for IVR flows, APIs, dial-plans, and system architecture.
• Collaborate with cross-functional teams for feature development, testing, and release.

Professional & Technical Skills

• Strong proficiency in Node.js or Python, with a deep understanding of socket programming.
• Hands-on expertise in SIP (Session Initiation Protocol) and WebRTC.
• Proven experience developing and deploying IVR systems and custom dial-plans.
• Familiarity with Asterisk, FreeSWITCH, Kamailio, or OpenSIPS.
• Solid understanding of telephony protocols, SIP signaling flows, and VoIP codecs.
• Experience with media servers, DTMF handling, and interactive voice prompts.
• Knowledge of WebRTC and NAT/firewall traversal techniques.
• Strong troubleshooting and debugging skills in real-time communication systems.
• Proficiency with Linux/Unix environments and scripting tools (Bash, Shell, etc.).
• Experience with SIP testing/debugging tools (Wireshark, sngrep, SIPp).
• Familiarity with RESTful APIs and backend integration for telephony platforms.
• Understanding of VoIP security, encryption, and NAT traversal best practices.

Additional Information

The candidate should have minimum 5 years of experience in Node.js. This position is based at our Pune office. Working from client office - 2 days/week is required. A 15 years full time education is required.