Hire Senior Voice AI Developers.
Engineers who ship voice agents that sound human — STT, LLM, TTS, with sub-second latency and graceful interruption.
80+
Products shipped
8+ yrs
In production
5–10 days
Time to start
24h
Reply time
Overview
Voice AI is the most demanding production AI you can ship. Latency matters: a conversational agent needs sub-second time-to-first-audio or it feels robotic. Interruption handling matters: real conversations interrupt. Persona matters: a voice agent that sounds awkward loses trust in seconds. Our voice AI developers ship production voice agents for customer support, sales, and accessibility — using Twilio, Vapi, LiveKit, or custom orchestration. We know the latency tradeoffs of every STT-LLM-TTS provider and how to design conversations that don't fall apart when the model gets confused.
Why Techyor.
Senior. Specialist. Shipping.
Sub-second latency or it doesn't ship
Time-to-first-audio under 1.5s with streaming STT, streaming LLM, streaming TTS. We measure and budget every hop.
Interruption-safe by design
Voice agents that handle real human conversation: interruptions, backchanneling, repair patterns. We don't ship turn-based bots.
Telephony-fluent
Twilio, Vonage, SIP integration. PSTN and WebRTC. We've connected voice agents to real phone numbers and handled compliance basics (call recording, consent flows).
What they cover.
Skills and stack.
Capabilities
- Voice platforms — Vapi, LiveKit Agents, Pipecat, Retell, custom orchestration
- STT — Deepgram, AssemblyAI, OpenAI Whisper (for non-realtime)
- TTS — ElevenLabs, Cartesia, Deepgram Aura, Azure Neural
- LLM orchestration — function calling, tool use, conversation memory
- Telephony — Twilio Voice, SIP, WebRTC
- Real-time audio — WebSocket streaming, opus codec
- Interruption handling — VAD, barge-in, repair conversations
- Latency optimization — streaming pipelines, parallel hops
- Compliance — call recording, consent, PII redaction in transcripts
Tech stack
The people behind the work.
Hire them directly.
Selected work.
Voice AI Developers in the wild.
A small slice of 5 projects where this role led the work.
Monster Fairings
A global e-commerce platform with AI-powered visualization, managing 5000+ fairings and serving riders across seven countries.
Firmable
AI-driven B2B Sales Intelligence platform providing buying signals and sales insights
SimpleTalk AI
Enterprise AI voice sales platform handling 147K+ calls across 12 languages, with multi-channel agents, white-label tenancy, and deep CRM integrations.
ConvertBankStatement
A specialized PDF-to-Excel conversion platform powered by a custom Python OCR engine, supporting 250+ bank formats and 30+ currencies for accountants and finance teams worldwide.
AiMusicService
AI-integrated music services e-commerce platform
How you can hire.
Three ways to engage.
Dedicated Full-Time
A senior developer working exclusively on your product, embedded into your team, sprint cycle, and rituals. Best for roadmap-driven work with continuous shipping.
Part-Time / Fractional
Two to three days a week of senior expertise. Ideal for early-stage teams, technical advisory, code review, or supplementing an existing in-house team.
Fixed-Scope Project
Defined milestones, outcomes, and timeline. Best when the brief is clear and you want a predictable budget. Includes design, QA, and handover.
How it works.
Simple. No theatre.
- 01
Quick intro call
A 30-minute conversation. Tell us what you're building, the stack you're on, and where you'd like help. No deck, no obligation.
- 02
We share our experience
We walk you through relevant projects we have shipped, the approach we would take, and the trade-offs to expect. Honest about what we are great at — and what we are not.
- 03
Start work
Mutual NDA, a clear scope, and a start date. We begin shipping that week. Daily updates and a single point of contact throughout.
What clients say.
On voice ai developer work.
Verified Upwork reviews from teams we've shipped for.
"Great freelancer — proactive, thinks outside the box, and responds quickly. I hired them for the second time and will definitely hire again for future projects. Thanks!!"
FAQ.
Common questions.
Vapi, Retell, LiveKit, or custom?
Vapi for fastest time-to-market with managed orchestration. LiveKit Agents when you want full control and self-hosting. Pipecat when you need Python-based orchestration. Custom when latency budgets, persona requirements, or compliance demand it.
What latency can we expect?
Time-to-first-audio: 800ms–1.5s end-to-end with streaming STT + streaming LLM + streaming TTS. End-to-turn (full response): 2–4s depending on response length. We measure each hop.
How do you handle interruptions?
Voice activity detection (VAD) on the user's mic. When the user speaks during the agent's turn, we cut TTS, capture the new utterance, and reroute. Repair turns ("sorry, can you say that again?") for low-confidence ASR.
TTS quality — which provider?
ElevenLabs for the most expressive voices (slower). Cartesia for low-latency real-time (faster). Deepgram Aura for cost-effective production. We benchmark on your script and persona.
Can you connect to a real phone number?
Yes — Twilio Voice + SIP integration is standard. We handle the inbound call, route to the voice agent, and connect outbound when the agent decides to transfer to a human.
Compliance — call recording, consent?
Yes — opt-in consent flows at call start, recording with user awareness, PII redaction from transcripts before storage. We follow jurisdictional rules (US two-party, EU GDPR-aware).
How fast can a developer start?
For most roles, within 5–10 business days from the intro call. We pre-qualify our bench so onboarding is contracts and access — not a hiring search.
Do you sign NDAs and IP assignment agreements?
Yes — every engagement starts with a mutual NDA and a clean IP assignment clause. All work product is your property the moment it's written.
What time zones do your developers cover?
Our team primarily operates in IST with 4–6 hours of overlap with US Pacific, full overlap with EU, and full overlap with AU East. We commit to overlap windows in writing.
Ready to start?
Let's chat.
Tell us what you're building. We will reply within 24 hours, hop on a quick intro call, walk you through relevant work we have shipped, and take it from there.
Prefer email? info@techyor.com
What are you looking for?
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