Designing the Orchestration Layer in Voice AI Systems
Technical HLD and LLD breakdown of the orchestration layer that coordinates ASR, LLMs, TTS, and business logic in real-time voice AI.
Orchestration Layer Architecture
The orchestration layer is the control plane of a conversational voice AI system.
High-Level Design
Core services include:
- Session Manager - Tracks conversation state
- Event Router - Routes events between ASR, LLM, TTS
- Policy Engine - Applies rules, guardrails, escalation logic
- Integration Dispatcher - Triggers external workflows
Cllr.ai uses a distributed orchestration model to handle high concurrency.
Low-Level Design
Session State Store
- Redis or low-latency DB
- Stores conversation turns, metadata, user context
Event-Driven Processing
- ASR emits transcript events
- LLM service consumes transcript events
- TTS triggered on response tokens
Interrupt Handling
- Voice Activity Detection (VAD) triggers cancel signals
- Ongoing TTS stream halted
- New LLM context generated
Conclusion
The orchestration layer enables modular AI services to behave like a single conversational system.
Wrap-up
Conversational Voice AI is moving fast — but turning models into reliable, real-time customer experiences requires the right orchestration, integrations, and infrastructure.
If you're exploring how to bring Voice AI into your product or operations, talk to our team to see how Cllr.ai helps businesses design, deploy, and scale real-time voice agents.