Automate Recruiting Follow-up with Custom Voice AI
The best voice AI for recruiting is a custom system built on a modern speech API. This approach avoids robotic-sounding voices and rigid scripts found in SaaS tools.
Building this system requires a clean list of candidates, defined trigger events from your Applicant Tracking System (ATS), and a clear follow-up script. Complexity grows if you need multiple conversational paths for different roles or need to integrate with a legacy ATS that lacks a modern API.
We built a voice follow-up agent for a 7-person staffing agency specializing in light industrial roles. They were manually calling 150 new applicants weekly. The system launched in 2 weeks and now handles initial outreach, saving each recruiter 5 hours per week.
What Problem Does This Solve?
Recruiting teams often try using their ATS's built-in email automation but find open rates are too low for time-sensitive roles. They turn to voice but hit a wall with off-the-shelf tools. Call-blasting services like CallFire are just dumb dialers. They play a pre-recorded message but cannot understand or react to a candidate's response. When a candidate says, “I’m busy, call me back,” the system has no way to process that information.
A 10-person recruiting firm tried one of these services to follow up on 200 recent applications. The message said, “Press 1 to speak to a recruiter.” Over 90% of candidates hung up immediately. The few who pressed 1 were dropped into a general queue, creating a confusing experience for both the candidate and the recruiter who had no context on the call. The tool could not answer simple questions or schedule a callback, resulting in a wasted budget and annoyed applicants.
Even modern recruiting CRMs with so-called AI features fall short. Their voice tools rely on low-quality, generic text-to-speech engines that make the outreach feel impersonal and cheap. Customization is often limited to inserting a candidate's name into a rigid template. You cannot change the voice, alter the intonation, or build logic to handle a simple question, making the interaction feel robotic and ineffective.
How Does It Work?
We start by connecting directly to your Applicant Tracking System's API to pull candidate data in real time. We use httpx for non-blocking API calls to fetch candidate name, phone number, and the specific job they applied for. Triggers, such as '24 hours post-application with no contact', are defined in a Supabase table, giving you an easy interface to adjust timing without changing code.
The core of the system is a Python application deployed on AWS Lambda. When a trigger condition is met, the function executes. It uses the ElevenLabs API for text-to-speech generation, which provides natural-sounding voices with latency under 400ms. The script is dynamic: "Hi, John, this is Sarah from Acme Staffing. I'm calling about your application for the forklift operator role. Is now a good time for a quick chat?"
If the candidate says "yes," we use the Twilio API to transfer the call directly to the assigned recruiter's phone line. If they say "call me back at 5 PM," a real-time transcription service captures the response, and the system schedules the callback, writing a note back to the ATS. The entire interaction, including a full transcript, is logged using structlog, and the average call duration is just 25 seconds.
The entire system is defined as code and deployed in a container. For a firm making up to 3,000 calls per month, the cloud hosting costs are typically under $50. We configure monitoring to send a Slack alert if the transcription API's error rate exceeds 5% for more than 10 minutes, ensuring system reliability is constantly tracked.
What Are the Key Benefits?
Engage Candidates in 24 Hours, Not 2 Days
The system automatically calls every new applicant within a day. This immediate follow-up increases response rates by over 30% compared to email-only sequences.
Pay for Usage, Not Recruiter Seats
A single, fixed-price build. Monthly cloud costs are based on call volume, not your team's headcount, avoiding expensive per-user SaaS fees.
You Get the Full Source Code
We deliver the complete Python codebase to your GitHub repository. You are not locked into our service and can have any developer extend it.
Alerts for Failed Calls, Not Silence
We configure monitoring that alerts you in Slack if calls fail or transcription errors spike. You know immediately if there is a system issue.
Writes Call Notes Directly in Your ATS
Connects to your existing Applicant Tracking System via API. Call outcomes and transcripts are logged automatically on the candidate record.
What Does the Process Look Like?
Week 1: Scoping and Access
You provide read-only API access to your ATS and define the follow-up scripts and logic. We deliver a technical spec outlining the triggers and call flows.
Week 2: Core Agent Build
We build the voice agent using Python and integrate it with the speech and telephony APIs. You receive audio samples of the voice for approval.
Week 3: Integration and Testing
We connect the agent to your ATS and run end-to-end tests with a small batch of test candidates. You receive a video walkthrough of the system.
Week 4: Launch and Monitoring
We go live with the first campaign. For 30 days post-launch, we monitor performance, tune the logic, and then hand over the runbook and source code.
Frequently Asked Questions
- How much does a custom voice AI agent cost to build?
- The cost depends on two main factors: the number of unique conversation paths and the quality of your ATS API. A simple follow-up agent with one script takes about 2 weeks. A system that handles scheduling and answers basic questions might take 4 weeks. After a 30-minute discovery call, we provide a fixed-price quote.
- What happens if a candidate says something the AI doesn't understand?
- The agent is designed for simple, direct follow-up, not open-ended conversation. If it cannot parse a response after two attempts, it defaults to a safe message like, 'I'm sorry, I didn't catch that. A recruiter will follow up with you via text message shortly.' An alert is logged, and the recruiter is notified to manually review the transcript.
- How is this different from a SaaS dialer like Orum or PhoneBurner?
- Tools like Orum are for sales reps to power through live call lists. They don't run automatically in the background. Syntora builds an autonomous agent that triggers on events in your ATS, like a new application. It engages candidates 24/7 without a human initiating the calls. It is for automated engagement, not manual outbound dialing sessions.
- Will this sound like a robot and annoy candidates?
- No. We use modern, generative voice APIs like ElevenLabs, not the robotic text-to-speech from a decade ago. The voices are natural-sounding with human-like intonation. We can even create a custom voice clone based on an audio sample you provide, so the agent sounds exactly like one of your team members, creating a consistent brand experience.
- What about TCPA and other call regulations?
- Compliance is critical. The system is configured to only call candidates who have explicitly opted in by providing their phone number on an application. We build in rules to respect time zones, calling only during acceptable business hours. You own the final compliance responsibility, but the system provides the technical controls to enforce your policies.
- Which Applicant Tracking Systems can you integrate with?
- We can connect to any ATS that has a modern REST API. We have built integrations for Greenhouse, Lever, and Ashby. If your ATS does not have an API, we can sometimes work with scheduled CSV exports, though this is not real-time. The initial discovery call confirms if your ATS API provides the necessary endpoints for the project.
Related Solutions
Ready to Automate Your Small Business Operations?
Book a call to discuss how we can implement ai automation for your small business business.
Book a Call