Build Outbound AI Voice Agent for B2B Appointment Setting (Bottleless Water Coolers)

We sell bottleless water cooler systems to small and mid-sized businesses. We have a working caller script and an operating system in place. We need an experienced voice AI developer to build and tune an outbound agent that calls business landlines, navigates the front desk, reaches the decision maker, and books a 15-minute in-person appointment for our rep. This is not a "set up a Vapi assistant" job. We need someone who has shipped outbound voice agents that survive real gatekeepers and knows why most of them fail. Scope of work Build the agent on an established platform (Vapi, Retell, LiveKit, or your recommendation — tell us why) Telephony setup, caller ID, local presence dialing Implement our existing call flow: gatekeeper navigation → decision-maker qualification → appointment booking → confirmation Branch logic for all four call outcomes: live person, gatekeeper block, IVR/phone tree, voicemail Voicemail detection with a defined action Reliable email capture over voice with character-level confirmation loop Calendar integration — create the invite and send it during or immediately after the call CRM logging with structured call outcomes (reached DM / gatekeeper block / voicemail / IVR / opt-out / booked / disqualified) Real-time opt-out detection writing to an internal DNC list Full transcript and audio logging Critical requirements Turn-taking and latency tuning. Endpointing thresholds, interruption handling, sub-500ms response. This is the difference between an agent that books and one that gets hung up on. We will evaluate you on this. Hard scope constraints. The agent sells the appointment Deliverables Working agent, that is able to book a meeting that is held in person Documented prompt and flow we can edit ourselves Test/regression harness with our scenario set Dashboard or reporting on call outcomes 60–90 minute handoff session so our team can maintain it Please include in your proposal A phone number I can call to hear an outbound agent you built. This is required — proposals without one won't be reviewed. How do you tune endpointing and interruption handling? Be specific about parameters. How do you handle email address capture over voice, given ASR error rates? Have you built agents that navigate gatekeepers or IVR trees? What worked? Engagement Starting with a paid pilot: one working agent, one vertical, tested and dialing. Ongoing optimization work available for the right person. Please quote for the pilot scope above and give a realistic timeline.