Voice AI Platform
Enterprise-grade voice AI infrastructure for automated customer service
Overview
Designed and built a production voice AI platform handling 1000+ daily customer service calls for a growing startup. The system combines real-time voice processing, LLM-powered conversation management, and voice synthesis to deliver natural, helpful interactions.
As both backend engineer and engineering manager, I owned the technical architecture while building and leading the engineering team through rapid iteration cycles.
Challenge
The client needed to scale their customer service operations without proportionally increasing headcount. Traditional IVR systems were frustrating customers with rigid menu trees, while human agents were overwhelmed with repetitive inquiries.
Key requirements included:
- Natural conversational flow that could handle complex multi-turn dialogs
- Real-time voice processing with minimal latency
- Seamless handoff to human agents when needed
- Comprehensive logging and analytics for conversation quality
Solution
Built a modular voice AI architecture with three core components:
1. Voice Processing Pipeline
Real-time speech-to-text using Azure Cognitive Services, optimized for Japanese language with custom vocabulary for domain-specific terms. Implemented streaming transcription to minimize perceived latency.
2. Conversation Engine
LLM-powered dialog management using carefully engineered prompts. The system maintains conversation context, handles interruptions gracefully, and knows when to escalate to human agents.
3. Voice Synthesis Backend
Text-to-speech with natural prosody and appropriate pacing for phone conversations. Implemented caching for common responses to reduce latency and costs.
Infrastructure
All infrastructure managed as code using Terraform across 5 Azure projects:
- Core API: FastAPI services on Azure Container Apps
- Voice Services: Azure Communication Services integration
- Management UI: Next.js dashboard for monitoring and configuration
- CI/CD: GitHub Actions with automated testing and deployment
- Observability: Structured logging, metrics, and alerting
Results
The platform successfully handles over 1000 calls daily with high customer satisfaction:
- 70% of inquiries resolved without human intervention
- Average handle time reduced by 40%
- Customer satisfaction scores maintained above baseline
- Engineering team scaled from 2 to 6 members during the project
Technology Stack
Backend
- Python
- FastAPI
- TypeScript
Frontend
- Next.js
- React
- TypeScript
Infrastructure
- Azure
- Terraform
- GitHub Actions
AI/ML
- OpenAI API
- Azure Cognitive Services
- Voice Synthesis