Build a Custom Voice AI Recruiting Agent
The best voice AI recruiting provider for a startup is a custom system you own. This approach avoids per-seat fees and integrates directly with your existing tools.
We built a voice agent for a 12-person recruiting firm processing 400 applicants per month. The system handles initial phone screens, cutting their time-to-hire from 28 days to 11 days. The entire build was completed in 3 weeks.
The scope ranges from simple inbound screening to complex outbound sourcing. A basic system can qualify applicants with 5-10 questions and schedule the next step. An advanced agent can manage multi-stage interview loops, handle rescheduling, and send automated follow-ups across different time zones.
What Problem Does This Solve?
Most startups first look at SaaS platforms like Paradox or MyAlly. They quickly find that these tools are built for large enterprises, with high monthly minimums and per-seat pricing that punishes growth. Their conversational flows are rigid; you cannot easily add role-specific technical questions, which makes them ineffective for screening engineers or other specialized roles. The candidate experience is often poor, forcing applicants into a third-party web portal to schedule interviews.
A common second attempt involves using Twilio Studio to build a simple phone menu. This fails because natural language is complex. A Studio flow can match keywords but cannot understand intent or context. If a candidate says, "I have experience with Python, but mainly for data analysis, not backend services," a keyword-based system breaks. It lacks the state management and conversational intelligence needed to handle real human dialogue, leading to a frustrating experience for the candidate and useless data for the recruiter.
How Does It Work?
We begin by mapping your exact screening and scheduling workflow into a state machine. The conversational logic is powered by the Claude API, which we fine-tune with your job descriptions and company data. This allows the agent to conduct a 15-minute screening call, asking 10-12 core questions while also handling conversational detours and answering candidate questions about company culture or benefits.
For the telephony layer, we use Twilio's Programmable Voice API. We use ElevenLabs for voice synthesis to create a natural-sounding agent, not a typical robotic one. Total response latency, from the moment the candidate stops speaking to when the agent replies, is kept under 800ms. This speed is critical for maintaining a fluid, natural conversation. The system is deployed on AWS Lambda, allowing it to handle up to 50 concurrent calls without performance degradation.
The agent integrates directly with your Applicant Tracking System (ATS) via its native API. We have built integrations for Greenhouse, Lever, and Ashby. After a successful screening, the system reads the hiring manager's Google Calendar, finds three open slots, and offers them to the candidate. A complete call transcript, summary, and pass/fail score are written to the ATS in under 5 seconds after the call ends.
We deploy the entire system as a Python FastAPI application. We use Supabase to store call logs and manage conversational state between interactions. All system events and errors are logged using structlog and piped to a dedicated Slack channel, providing real-time visibility into performance. The typical AWS hosting cost for processing 1,000 calls a month is under $50.
What Are the Key Benefits?
From Kickoff to First Call in 4 Weeks
A complete system handling screening and scheduling is deployed in under 20 business days, reducing your time-to-hire immediately.
Own Your System, Kill Per-Seat Fees
A one-time build cost replaces recurring SaaS fees. Your only ongoing cost is for cloud usage, which is a fraction of a typical subscription.
Full Source Code in Your GitHub
You get the entire Python codebase and a detailed runbook. If your needs change, any developer can modify the screening logic without vendor dependency.
Real-Time Alerts for Dropped Calls
We configure Slack webhooks for instant notifications if an API fails or a call drops, with automated SMS retry logic built in for the candidate.
Connects Natively to Your ATS
Direct API integration with Greenhouse, Lever, or Ashby. Recruiters see all data in the tool they already use, with no context switching.
What Does the Process Look Like?
Week 1: Scoping & ATS Integration
You provide read-only API keys for your ATS and calendars. We map your current recruiting workflow and define the AI agent's screening questions.
Week 2: Core Agent Development
We build the conversational logic using the Claude API and train the voice agent. You receive audio samples and transcripts for review and feedback.
Week 3: Deployment & Testing
We deploy the system on AWS Lambda and connect it to a dedicated Twilio phone number. You receive a staging environment to run test calls.
Week 4: Handoff & Monitoring
After a week of live monitoring, we transfer the GitHub repo and AWS account ownership. You receive full documentation and a handoff session.
Frequently Asked Questions
- How much does a custom voice AI recruiter cost?
- Pricing is fixed-scope based on complexity. A system for screening inbound applicants for one role type is a 3-week build. Adding outbound sourcing, multi-language support, or complex scheduling with multiple stakeholders increases the scope. We provide a fixed-price quote after a 30-minute discovery call where we can define the exact requirements for your recruiting process.
- What happens if the AI misunderstands a candidate or a call drops?
- The system is designed for graceful failure. If the AI cannot understand a response after two attempts, it politely ends the call and flags the recording for human review. If a call drops, it automatically sends the candidate an SMS to reschedule. A log of all failed interactions is sent to your recruiting coordinator's dashboard for follow-up.
- How is this different from using a SaaS tool like Paradox?
- Paradox offers a managed platform with per-seat or per-hire pricing, which can be costly for startups. You are limited by their pre-built conversation flows. A custom build from Syntora means you own the code, pay only for cloud usage, and can define highly specific screening logic for technical roles that off-the-shelf tools cannot handle effectively.
- Will candidates be turned off by talking to a robot?
- For initial screens, candidates prefer a fast and consistent experience over waiting days for a human. The AI is available 24/7 and provides immediate feedback. We ensure the agent clearly identifies itself as an AI assistant at the start of the call to set clear expectations. The efficiency is a significant improvement over the typical black box application process.
- How hard is it to change the screening questions later?
- The questions are stored in a simple JSON configuration file. Changing them requires editing this file and redeploying the AWS Lambda function, which takes about 5 minutes for a developer. The process is documented in the runbook you receive. For non-technical teams, we offer a flat monthly maintenance plan to handle these kinds of updates for you.
- What do we need to provide on our end?
- You need an Applicant Tracking System (like Lever or Greenhouse) with API access and a corporate Google Workspace or Microsoft 365 account for calendar integration. You do not need an in-house engineering team. We handle the entire build, deployment, and handoff. We will help you set up your own AWS and Twilio accounts so you have full ownership.
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