Value Delivered — 2-Day Production Build
In two days, we built a production-ready multi-tenant voice AI receptionist platform serving 4 businesses on a single bare-metal GPU server. The system handles inbound phone calls via Twilio SIP, qualifies callers through a 3-gate conversational flow, offers connect-now or scheduled callback, and routes to human agents — all self-hosted with zero cloud AI dependency.
Single container serves 4 businesses. DID → Redis → per-tenant prompt, voice, greeting, transfer target. New tenants onboard in minutes via automated script.
Compensates for Qwen3-8B's ~0% native tool call rate. Caller demand, caller confirm, agent text fallback — 100% transfer reliability.
SlotTracker extracts 13 fields from caller speech. PolicyEngine handles transfer/callback/hangup deterministically. LLM owns conversation only.
4-layer stack: DTLN noise suppression → Silero VAD → STT confidence filter → interruption handling. Reduced noise interruptions from 6+/call to 1-2.
Agent asks name, business name, address naturally after qualifying. Call summary JSON persisted with pre-formatted SMS text.
25 scenarios, 104 unit tests. Automated baseline testing across all tenants on every prompt/model change.
Every call flows through deterministic defense layers (blue) before reaching the non-deterministic LLM (amber). The deterministic path runs synchronously and always wins the race against the async LLM.
| Metric | Value | Notes |
|---|---|---|
| Tenants live | 4 | GDS, CRU, noboxAI, North Group RE |
| Service re-ask rate | 4% (was 60%) | Gate 1 reframe + SlotTracker |
| Conversation quality | 100% | 25 scenarios, all natural |
| Transfer reliability | 100% | 4-layer fallback architecture |
| Native tool call rate | 8% | Fallback compensates for 92% |
| Avg response latency | 293ms | Qwen3-8B + /no_think |
| Call summaries persisted | 32 | JSON with SMS text pre-formatted |
| Unit tests | 104 | Was 47 at session start |
| Scorecard scenarios | 25 | Across all 4 tenants |
| Item | Priority | Status | Dependency |
|---|---|---|---|
| Toll-free A2P verification | High | Pending Twilio | Unblocks SMS delivery |
| STT confidence data | High | Designed | Custom Whisper wrapper |
| CRU renewal re-ask fix | Medium | Known issue | Prompt iteration |
| Production call volume | Medium | Accumulating | Time (50+ calls) |
| Log persistence | Medium | Planned | Docker logging driver |
| Transfer classifier | Low | Designed | 100+ call summaries |
| Tool-tuned SLM eval | Watch | Future | Qwen3.1 / Llama 4 |