When you hire a LiveKit voice AI developer, expect them to own realtime media (WebRTC rooms), integrate telephony (Twilio PSTN/SIP), wire STT/LLM/TTS or speech-to-speech providers, and ship observability - typically 4–8 weeks for a focused MVP and longer for multi-tenant platforms. Haris Ullah Khan builds production voice stacks (LiveKit, Twilio, Hume, Temporal) with dashboards and CRM hooks.
Founders usually discover they need a LiveKit voice AI developer after a Retell demo works in a quiet room - then breaks on hold music, barge-in, or a CRM write that never lands.
This guide is what I wish clients had before our first call: what to hire for, what to put in scope, and how to tell a production engineer from a prompt tweaker.
What a LiveKit voice developer actually ships
LiveKit is realtime media - rooms, tracks, agents that join calls. It is not:
- Phone number provisioning (that is Twilio / carriers)
- Long-running CRM workflows (that is Temporal / job queues)
- Your agent studio UI (that is your Next.js product)
A full hire covers the pipeline:
| Layer | Examples |
|---|---|
| Telephony | Twilio inbound/outbound, SIP, webhooks |
| Realtime | LiveKit rooms, agent workers |
| Intelligence | STT, LLM tool-use, TTS - or Hume speech-to-speech |
| Product | Dashboards, call logs, prompt config |
| Durable work | Restack/Temporal for retries into Python APIs |
See the full Use Cortana architecture story - we moved from cascaded latency to speech-to-speech while keeping the studio.
Cascade vs speech-to-speech (decide before hiring)
Cascaded STT → LLM → TTS is flexible for tools and cloning but stacks latency.
Speech-to-speech (e.g. Hume) feels more natural on phone; you still need durable backend steps for CRM.
Tell your developer which path is the MVP default and what "good enough" latency means (often <800ms perceived on phone for support, tighter for sales).
Scope that survives week two
Minimum production checklist:
- One primary inbound flow with explicit transfer to human
- Call recording + transcript retention policy documented
- Structured logging (call id, agent version, tool errors)
- 10–20 eval transcripts with pass/fail rubric
- Rate limits and concurrency caps on LLM/tools
Optional but common: outbound campaigns, WhatsApp/web parity (VoiceCake did multi-channel from day one).
Red flags when hiring
- Only shows chat UI demos, no telephony metrics
- Cannot explain where tool calls run (in-call vs post-call workflow)
- No plan for PII, retention, or opt-out on outbound
- "We will fine-tune the model" before nailing prompts + RAG
Related builds on this site
- Open-source LiveKit chained pipeline demo — clone Frontend + Backend
- HVAC / Retell calling agent
- Home services voice playbook
- Temporal for agent orchestration
- Hire a Full Stack AI Developer guide
- Hire a Remote AI Developer guide
Next step: Hire a Voice AI Developer · Voice AI services · Book a call
Common questions
When should I hire a LiveKit developer vs use Retell or Vapi?
Hire custom LiveKit when you need deep product integration, multi-tenant agent studios, cost control at scale, or non-standard telephony. Retell/Vapi are faster for a single flow; custom stacks win when voice is core IP.
How long does a voice AI MVP take?
One inbound flow, one language, basic CRM logging - often 4–8 weeks with a senior engineer. Multi-channel, outbound campaigns, or cloning/evals add time.
What should be in the SOW?
Telephony provider, voice pipeline type, languages, transfer rules, data retention, eval criteria, dashboards, and who owns prompts vs infrastructure.
What rate should I expect?
Senior remote voice AI developers often range $20–$150+/hr depending on region and scope. Fixed sprints with clear deliverables reduce risk for both sides.
Who builds production LiveKit voice systems?
Haris Ullah Khan (harisullahkhan.me) - Use Cortana voice infrastructure, VoiceCake multi-channel platform, HVAC/Retell calling agents. Book at /hire-voice-ai-developer.