Fourteen lessons covering the complete WebRTC and real-time audio pipeline that every video conferencing product depends on. We walk the entire signal path — capture, AEC3, noise suppression, AGC, packetization, jitter buffer (NetEQ), packet loss concealment, FEC and redundancy (RED), bandwidth estimation, and rendering — and finish with a diagnostic runbook for the production audio failures you actually see: one-way audio, echo, robotic playback, AEC convergence stalls, and Bluetooth speakerphone issues.