Principal Engineer (VoIP Platform)

What You'll Do:

• Design and implement VOIP (signaling and media)infrastructure usingFreeSWITCH, Kamailio/OpenSIPs,andRTPEngine.
• 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 forscalability, observability, security, and resiliencyof 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 theTelephony / VoIP / CPaaSdomain.
• Strong knowledge ofVoIP Protocols(SIP/SDP, RTP/RTCP),Networking fundamentals(UDP/TCP/IP, DNS, MPLS),QoS(latency, jitter, packet loss mitigation).
• Hands-on experience withSession Border Controller (SBC), Media Servers and WebRTC.
• Expert-level understanding ofSIP, RTP, NAT traversal (ICE/STUN/TURN), and VoIP security (TLS, SRTP, fraud prevention).
• Hands-on development experience withFreeSWITCH, Kamailio/OpenSIPs, and RTPEngine.
• Experience in designingcarrier-grade telephony plaformsserving millions of calls.
• Strong systems programming and debugging skills inC/C++
• Strong troubleshooting skills, with experience usingnetwork monitoring and debugging tools.
• Familiarity with distributed systems and cloud-based deployments (AWS, GCP, Azure)
• Excellent problem-solving, debugging, and performance tuning skills