Dung N.

- Python (FastAPI, Django), Php (Laravel), JavaScript (Node.js, Express), Java, Kotlin, Dart, Lua, Flutter - Custom applications for Asterisk, FreePBX, FreeSwitch, FusionPBX, Kamailio, dSIPRouter,... - VoIP Call control and configuration API Backend (AMI, ARI, ESL) - ASR(STT)/TTS/STS Voice agent API - Ringless Voicemail Drop (VM Access point and 2 call) - Direct-to-mailbox delivery (Diversion header) - Auto-dialer - FCM Push Notification for SIP client on Android - WebRTC webphone - AI integration: Vosk API, Openai-whisper, GenAI, Twilio API, Deepgram (gRPC/REST/WebSocket APIs) - AI Voice Agent: VAPI, Retell - LM Training with Kaldi - Google ML, Firebase - VoIP Provider: DIDLogic, VoIP.ms, Plivo, CallCentric, Twilio, Signalware, Telnyx - LiveKit, Livekit-SIP - Automation: n8n, make - build xiangqi engine Pikafish for Android