Principal Engineer (VoIP Platform)

What You'll Do:

• Design and implement VOIP (signaling and media) infrastructure using FreeSWITCH, Kamailio/OpenSIPs, and RTPEngine.
• Architect session border controllers (SBC), NAT traversal, load balancing, and failover strategies.
• Define standards for call routing and audio quality optimization (codecs, jitter, etc.)
• Lead initiatives for scalability, observability, security, and resiliency of our voice infrastructure.
• Troubleshoot live trac and provide technical leadership during major incidents.
• Collaborate with Backend and API teams to design provisioning, billing, and call analytics APIs.
• Evaluate and onboard open-source tools or commercial carriers as needed.
• Coach and mentor junior/lead engineers in VoIP best practices.

What Makes You Qualified

• 12+ years of hands-on experience in the Telephony / VoIP / CPaaS domain.
• Strong knowledge of VoIP Protocols (SIP/SDP, RTP/RTCP), Networking fundamentals (UDP/TCP/IP, DNS, MPLS), QoS (latency, jitter, packet loss mitigation).
• Hands-on experience with Session Border Controller (SBC), Media Servers and WebRTC.
• Expert-level understanding of SIP, RTP, NAT traversal (ICE/STUN/TURN), and VoIP security (TLS, SRTP, fraud prevention).
• Hands-on development experience with FreeSWITCH, Kamailio/OpenSIPs, and RTPEngine.
• Experience in designing carrier-grade telephony plaforms serving millions of calls.
• Strong systems programming and debugging skills in C/C++
• Strong troubleshooting skills, with experience using network monitoring and debugging tools.
• Familiarity with distributed systems and cloud-based deployments (AWS, GCP, Azure)
• Excellent problem-solving, debugging, and performance tuning skills