Full Stack Developer

Sentire Systems

AI voice platform that gives service businesses a 24/7 receptionist — answers calls, books appointments, and recovers missed callers automatically

Next.jsFastAPIOpenAI GPT-4oLangChainDeepgramElevenLabsTwilioSupabaseGoogle Calendar APIRedisAWS

Overview

Sentire Systems is a production-grade multi-tenant AI voice platform designed to automate customer communication, inbound calls, and appointment scheduling for service-based businesses. The platform provides businesses with dedicated AI voice agents that answer calls 24/7, understand customer intent through natural conversation, schedule appointments in real time, and recover missed callers via SMS — all without a human receptionist. Traditional businesses lose potential customers due to missed calls, delayed responses, and manual scheduling. Sentire replaces those workflows entirely with an always-on, intelligent voice assistant.

The Challenge

Delivering natural voice conversations required sub-2-second end-to-end latency across a full real-time pipeline: telephony routing, speech-to-text, LLM reasoning, text-to-speech, and audio playback. Supporting multiple businesses on one platform demanded strict tenant-level data isolation with zero cross-tenant leakage. The system also needed to handle 30+ concurrent calls per instance without degrading response quality, and support cross-industry flexibility — salons, clinics, professional services — through a configurable agent architecture rather than separate codebases.

How We Solved It

1

Voice Interaction Layer

Real-time voice pipeline: Twilio manages business phone numbers and call routing, audio streams over WebSockets, Deepgram converts customer speech to text, OpenAI GPT-4o processes conversation, and ElevenLabs generates natural voice responses. Optimized at every stage to achieve sub-2-second round-trip conversational latency.

2

AI Conversation Engine

Powered by OpenAI GPT-4o with LangChain orchestration. The engine receives live call audio, converts speech to text, detects customer intent, maintains multi-turn conversation context, executes business workflows (scheduling, FAQs, escalation), and generates responses — all within a single streaming pipeline to minimize delay.

3

Appointment Automation

Deep Google Calendar integration enables real-time availability checks, conflict-free booking, business-hours enforcement, and calendar synchronization. Customers complete full appointment bookings entirely through voice — zero clicks, zero forms, zero wait.

4

Multi-Tenant SaaS Architecture

Each business receives a dedicated phone number, isolated AI configuration, separate customer data, independent dashboard, and custom branding. Supabase Row-Level Security policies enforce complete tenant separation at the database layer, ensuring no cross-tenant data access is possible.

5

Dashboard & Management System

A full business dashboard covers call history, conversation transcripts, audio recordings, appointment analytics, AI personality configuration, business hour settings, agent prompt management, SMS logs, missed call recovery, and branding customization — giving owners complete visibility without sitting at the front desk.

6

Missed Call Recovery & SMS Automation

When a caller hangs up before connecting, the platform automatically sends an AI-powered SMS with available times, handles the customer's reply, and confirms the booking — converting missed calls into appointments entirely over text with no human intervention.

Platform & Landing

Features & Architecture

Results & Impact

Sub-2s Conversational Latency

End-to-end voice pipeline optimized across telephony, STT, LLM reasoning, and TTS to deliver human-like conversation speed.

30+ Concurrent Calls

Horizontal scaling architecture handles 30+ simultaneous voice calls per instance without degrading response quality or latency.

24/7 Call Coverage

Dedicated AI voice agent answers every inbound call around the clock — no missed calls, no voicemail, no wait times.

Zero Double Bookings

Real-time Google Calendar availability checks prevent scheduling conflicts — every slot verified before a booking is confirmed.

Missed Call SMS Recovery

Automatically follows up on missed calls with available times over SMS and converts replies into confirmed appointments.

Full Multi-Tenant Isolation

Supabase Row-Level Security ensures complete per-tenant data separation across all businesses on the shared platform.

Technical Architecture

FrontendNext.js + Tailwind CSS — landing site, client login, business dashboard (call logs, appointments, analytics, agent config, SMS logs, branding)

BackendPython FastAPI — call orchestration, WebSocket audio streaming, multi-tenant management, appointment workflows, SMS automation

AI / LLMOpenAI GPT-4o + LangChain — intent detection, multi-turn conversation, business rule execution, response generation

Voice PipelineDeepgram — real-time speech-to-text; ElevenLabs — natural text-to-speech voice generation; Twilio — telephony, phone number management, WebSocket audio routing

SchedulingGoogle Calendar API — real-time availability checks, conflict-free booking, business-hours enforcement, calendar sync

Database & AuthSupabase PostgreSQL + Row-Level Security — multi-tenant data isolation, call records, transcripts, appointments; Supabase Auth

Caching & InfraRedis — session caching, real-time state management; AWS — scalable cloud deployment with horizontal scaling for concurrent call handling