A voice assistant is ready only when defined journeys survive real exchanges under agreed recognition, latency, identity, escalation, and channel limits.

Voice work is judged inside the exchange itself. We build around defined journeys, with clear requirements for speech recognition, turn-taking, latency, identity, escalation, and channel limits. Representative conversations show where the assistant works, where it should stop, and what context the human team receives. Your service owner receives a tested assistant dossier, journey and identity record, conversation review, and release handoff tied to the channel conditions exercised.

Illustration of Voice AI Assistant Development: a team shaping a conversational AI experience and its guardrails

Some of the 500+ brands we've worked with

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  • Kuveyt Türk
  • Shiftdelete
  • Bluemint
  • Grandvision
  • GS Store
  • Amazon
  • BMW
  • Shell
  • Hyundai
  • PepsiCo
  • Red Bull
  • Decathlon
  • MediaMarkt
  • Bayer
  • Sanofi
  • EY
  • KPMG
  • GE
  • 3M
  • Domino’s
  • Lexus
  • Trendyol
  • Hepsiburada
  • Yandex

We start from real journeys and end with a tested assistant. Any boundary expands only after a review with your owner.

  1. Trace the spoken journeys

    We walk each in-scope journey and trace how turn-taking, recognition, identity, escalation, and channel constraints behave along it. Exceptions that need a different path are marked before the build begins. Scope is set by your service owner, who confirms the journeys and channel limits.

  2. Build the smallest testable slice

    We assemble the smallest slice of the assistant that can carry the agreed journeys end to end, wiring in only the dependencies those journeys need. Anything the slice hasn't exercised stays outside the accepted boundary. Before we test the slice, your service owner approves its access and channel boundary.

  3. Test representative and adverse exchanges

    Representative and failure-case conversations run through the slice, then we review recognition, turn-taking, latency, identity, and escalation journey by journey. What each exchange exposes goes on the exception list. Every exception goes to your service owner for the final call, including which ones need a person.

  4. Hand the channel team the record

    Accepted behavior, open exceptions, the responsible owner, and a date for the next review go into one record. The operating team reads it and knows which journeys may ship and which must wait. The handoff and its next review date take effect when your service owner accepts them.

The assistant arrives together with its evidence. The operating team receives the conversations, channel conditions, and decisions used to accept each journey.

  • Playbook

    Tested voice assistant channel operations dossier

    The working slice, with the channel limits, escalation path, and operating steps agreed for the journeys it was tested on.

  • Matrix

    Voice journey and channel record

    One place to look up the representative conversations, channel constraints, identity rules, escalation routes, and build dependencies.

  • Test evidence

    Representative conversation review

    A journey-by-journey account of how speech recognition, turn-taking, latency, identity, and escalation behaved in the conversations we ran.

  • Playbook

    Voice-journey release conditions and owner record

    The record the channel team uses after handoff. Tested journeys, open conversation cases, the responsible owner, the escalation route, and the date of the next review.

A voice journey has to stand up inside clear channel, identity, and escalation limits before it carries daily traffic. This build produces that proof.

A good fit when

  • Your first voice journeys are named, but nobody has accepted the channel limits or taken responsibility for the result.
  • Representative conversations exist, but they do not cover the accents, channel constraints, identity checks, or escalation failures the build must face.
  • Exceptions reach the service team, but nobody has decided which ones need a person, which block release, or when the assistant must stop.
  • Speech recognition works in a demo, yet turn-taking, latency, identity, escalation, and channel limits have not been tested journey by journey.
  • A working assistant exists, but it carries more dependencies than the agreed journeys need and its accepted access boundary is unclear.
  • Representative conversation traces exist, but the service owner still lacks one file linking acceptance tests, exception decisions, and the operating handoff.
  • The team wants to release the assistant, but the highest-priority journeys do not yet have test evidence tied to a clear gate.

Better handled as other work when

  • You need voice journeys, channel access, or identity permissions released before testing. The service owner must review those boundaries against real conversations.
  • You need perfect speech recognition, response quality, or latency in every condition. This build only supports decisions about the journeys and channels tested.
  • You need the assistant operated in production after handoff. Ongoing channel support and work beyond the agreed build require a separate scope.

If one of these is closer to your situation, start here instead: More on AI chatbot development

This is the part of Zeo that writes and ships code. Our senior engineers build agents, chatbots, and RAG pipelines, along with the automation and data work around them, and they keep operating those systems once they're live. We've worked with more than 500 brands since 2011.

  • ElevenLabs

    provides the spoken voice runtime and natural response playback

  • Deepgram

    runs real-time speech recognition and turn-taking inside the latency budget

  • LangChain

    keeps spoken context, tools, retrieval, and handoff state connected

  • Voiceflow

    maps spoken journeys, interruptions, repairs, and escalation points

  • Langfuse

    traces each spoken exchange from transcript through handoff

  • Guardrails AI

    checks spoken responses before they are ever read aloud

Share the journey, representative exchanges, and the person who approves its limits. We'll shape the smallest useful build around it.
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What has to be ready before the build starts?

The voice journeys and representative conversations, plus what you already know about them. That means speech recognition and turn-taking constraints, latency expectations, identity and escalation rules, and any current evidence. Each piece needs an owner, and the result needs someone who signs off. Before building we also confirm which sources and systems the assistant may use.

How much of the testing runs through your own AI agents?

Some of the routine parts. Approved agents can organize conversation evidence, compare coverage, and draft test cases, always inside the agreed workspace. A Zeo specialist checks their sources, labels, and conclusions. The agents never widen channel access, and they never decide that an exception is safe to release.

What gets reviewed before the assistant goes live?

We listen back to the representative journeys and check how identity and escalation were handled. We also look for the places where the assistant slows down, interrupts the caller, or needs a person to step in. The release decision stays tied to those conversations and the channel limits they ran under.

What can't this build promise?

We don't claim the assistant will understand every speaker, meet every latency need, or handle every journey without oversight, so the evidence supports a decision only about the examples, channels, constraints, and exceptions we tested.