Hire voice AI engineers who build agents for live phone calls
Hire voice AI engineers from our in-house team in India who connect telephony, speech recognition, an LLM and speech synthesis into one agent, then hand the call to your team when it should. You interview the shortlist and choose who joins.
Clutch 4.8/5 from 33 verified reviews
50+ AI systems in production · ISO 9001:2015
to matched profiles
Each stage streams into the next, so the caller hears a reply quickly.
Trusted by teams at
What a voice AI engineer does on your team
A voice agent is judged on the call, so most of the engineering goes into timing, recognition and the moments where the agent passes the caller to a person.
- What does a voice AI engineer do?
- A voice AI engineer builds software that holds a spoken conversation, usually over a phone line. The work joins telephony, speech-to-text, a language model with access to business systems and text-to-speech, then tunes the delay between turns, interruptions, misheard details and the handoff to a person.
Voice agent developers available to hire
Hire one engineer for a single call flow, or pair roles into a small voice pod.
Voice agent engineer
Owns one call flow, such as booking or order status, from the phone number to the record it updates.
See AI voice agent developmentSpeech pipeline engineer
Tests speech-to-text and text-to-speech providers on recordings of your own callers and picks the ones that hold up.
Telephony integration engineer
Connects the agent through telephony APIs or a SIP trunk to your PBX or contact-centre platform, including transfers to your team.
Conversation and tools engineer
Writes the prompts and tool calls that let the agent check a calendar, look up an order or update your CRM during the call.
Hire AI agent engineersVoice QA engineer
Runs scripted test calls, reviews transcripts and tracks where calls go wrong after each release.
Chat and voice assistant engineer
Builds a chatbot and a voice agent on the same knowledge and integrations, so the second channel costs less to add.
See AI chatbots and assistantsWhere voice agents fail on live calls
A voice demo in a quiet room tells you little. Live callers interrupt, mumble and ask for things the script never covered, and these are the four failures our engineers design for.
Long silences
Waiting for the full transcript, then the full reply, then the full audio adds up to a pause callers notice. Speech recognition, the model and speech synthesis stream into each other, so the reply starts sooner.
Talking over the caller
An agent that keeps speaking after the caller starts to talk sounds broken. Barge-in stops the agent speaking as soon as the caller interrupts.
Misheard details
A wrong date or reference number turns into a wrong booking. Providers are tested on your own recordings, and dates, names and reference numbers are read back for confirmation.
Calls with no way out
Callers who cannot reach a person hang up and call again. The agent transfers the call when the caller asks or a rule you set applies, with a summary and transcript for your team.
How we vet voice AI engineers
Every engineer on the roster is full-time and in-house, and passed these checks before you see a profile.
Systems design interview
Candidates design a call flow under fixed limits on delay, cost per minute and handoff rules.
Live build exercise
Candidates build a working component, such as a tool call during a conversation or a transfer step, and we review it for code quality and error handling.
Production work checked
References and work samples confirm AI features shipped to production users.
Your own interview
You interview the shortlist and choose. Nobody joins your team until you approve them.
Hire a voice AI engineer this month
Tell us the call flow and your phone system. Matched profiles reach you within 48 hours.
The voice stack our engineers work in
Providers are chosen per project, after tests on your own call recordings and your call volume.
Cost to hire voice AI engineers
Dedicated voice AI engineers start from $1,799 a month, full-time, the same rate as every other role. Telephony, speech and model usage are billed by the providers per minute or per token.
| Dedicated team | Fixed-scope project | Team extension | |
|---|---|---|---|
| How it is priced | From $1,799 a month per engineer, full-time | Fixed quote after a free discovery sprint | Billed monthly per engineer |
| Best for | A contact centre automating more call flows over time | A defined build with agreed milestones | A specific skill gap in a team you already run |
| Who manages day to day | You, inside your process | ScalaCode, against agreed milestones | Your leads, with our engineers reporting in |
Monthly means full-time and dedicated, 160 hours. Compare every option on the Engagement models page.
Talent Matched: voice screening in a recruitment SaaS
On Talent Matched, candidates answer screening questions out loud. Speech recognition turns each answer into text, and the platform scores it for communication, clarity and confidence. A private LLM with semantic search then ranks how well the person fits the role. The answers are recorded, so nobody is on a live call. A phone agent would add the telephony, streaming and handoff work described above.
Candidate ranking time, per the client
One team, 14 years of shipping
projects shipped since 2012
clients across 45+ countries
AI systems running in production
years building software, since 2012
What clients say about our AI engineers
Verified reviews from Clutch and GoodFirms, and clients on camera.
33 verified reviews on Clutch
Clutch review★★★★★“What stood out to us as most impressive and unique about ScalaCode was their ability to humanize complex AI.”
Clutch review★★★★★“What sets ScalaCode apart is their technical AI expertise and an understanding of a client's organizational ethos.”
GoodFirms review★★★★★“They built a high-performance, AI-powered platform that transformed video engagement for learning.”
Clutch review★★★★★“They managed to balance technical skill with an understanding of the marketing world.”
Clutch review★★★★★“Their team often proposed innovative features we hadn't considered.”
Clutch review★★★★★“They didn't just build an algorithm; they built a tool that respects the nuances of Indigenous reconciliation.”
Clutch review★★★★★“What I found impressive about ScalaCode was their ability to listen to the soul of an educational mission.”
Hire voice AI engineers FAQs
Dedicated voice AI engineers start from $1,799 a month, full-time, the same as every other role.
How much does it cost to hire a voice AI engineer?
Dedicated voice AI engineers start from $1,799 a month, full-time and billed monthly. If you want ScalaCode to own the delivery, a voice agent proof of concept on one call flow starts at $4,999, and telephony, speech and model usage are billed by the providers per minute or per token.
Which voice platforms and providers do your engineers use?
For telephony they use Twilio, Vonage, Plivo, Telnyx or a SIP trunk. Speech-to-text runs on Deepgram, AssemblyAI or Whisper, and text-to-speech on ElevenLabs, Cartesia, OpenAI TTS or Azure AI Speech. For real-time voice they work with the OpenAI Realtime API, Gemini Live, LiveKit and Pipecat.
How do your engineers keep a voice agent fast enough for a phone call?
Speech recognition, the model and speech synthesis stream into each other, so the agent starts its reply before the whole answer is written. The agent stops speaking as soon as the caller interrupts, and providers and models are chosen partly on how quickly they respond on your test calls.
Can the voice agent hand a call to a person?
Yes. The agent transfers the call when the caller asks, when its confidence drops or when a rule you set applies, such as a complaint or a payment dispute. Your team receives a short summary and the transcript, so the caller does not have to repeat themselves.
Can the engineer connect the agent to our phone system and CRM?
Yes. The agent connects through telephony APIs or a SIP trunk to an existing PBX or contact-centre platform. During the call it reaches Salesforce, Microsoft Dynamics or your booking and order systems through their published APIs.
How do you handle accents and background noise?
Speech recognition providers are tested on recordings of your own callers before one is chosen, because results vary with accent, language and line quality. Dates, names and reference numbers are read back for confirmation, and the agent hands the call to a person when it still cannot understand the caller after a retry.
How fast can a voice AI engineer start?
Matched profiles reach you within 48 hours of the first call. After you interview and choose, onboarding takes about a week.
Should we buy a voice agent platform or hire engineers?
Buy a hosted platform when the call flow is standard and the platform already connects to your systems. Hire engineers when the agent has to work with your own systems and data controls, or when call volume makes per-minute platform fees a large line in the budget. If you want a text channel too, chatbot developers can build it on the same knowledge and integrations, and our AI voice agent development team can own the whole build if you prefer.
Who owns the code, prompts and call data?
You do. The code, prompts, call flows and test sets are assigned to you under the contract and NDA. Recordings, transcripts and logs stay in your cloud account under your retention policy.
Which time zones do your engineers cover?
Our engineers work from India and overlap with US, UK and European business hours. For US clients the standard overlap is 4 to 6 hours of the US working day.
Your engineers work in your hours
Timezone overlap is built in. Your matched engineers keep 4 to 6 hours of daily overlap with US hours and a full working day with the UK, Europe and the Middle East, so standups, reviews and fixes land during your working day.
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Tell us the call flow and we will send voice engineers matched to it
- Profiles matched on voice stack and domain within 48 hours
- You interview and choose who joins
- You commit only after you choose
“They delivered on time and even offered ideas I hadn't considered.”
John-Paul Hatala, CEO, SnagPad