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ProductJanuary 15, 2025·6 min read

The 3D AI Interviewer: Why Candidates Prefer It to Phone Screens

We built a Three.js avatar that conducts real interviews. Here's what we learned about candidate experience, bias reduction, and interview quality.

Phone screens are inconsistent, time-consuming, and biased. Different interviewers ask different questions. Candidates are judged on how they sound, not what they say. And the whole process takes 30 minutes of a recruiter's time per candidate — time that could be spent on candidates who actually made it through screening.

We built a 3D AI avatar that conducts structured interviews — and the results surprised us.

Why 3D?

We tried text-based chat interviews first. Candidates found them impersonal and rushed through answers. We tried audio-only AI. Candidates found it uncanny — the disembodied voice without visual feedback felt off.

A 3D avatar hits a different register. It's clearly not human, but it's engaging. Candidates report feeling less judged and more willing to give honest, detailed answers. The visual presence creates a sense of conversation rather than interrogation.

How It Works

The avatar is built with Three.js and powered by AWS Bedrock. The full interview flow:

  • Candidate receives a unique link and starts the interview at their convenience
  • The avatar introduces itself and explains the process
  • Questions are generated dynamically based on the job description and the candidate's resume
  • Responses are transcribed in real-time using Whisper
  • Each response is scored against the job requirements
  • Video is analyzed for confidence, eye contact, fidgeting, and emotional tone
  • A structured report is generated with strengths, weaknesses, and a hire/no-hire recommendation

What We Measure

Beyond the transcript, we analyze several dimensions of candidate performance:

  • Confidence score: Posture, voice steadiness, eye contact percentage
  • Engagement: Response length, follow-up depth, question comprehension
  • Communication: Clarity, structure, vocabulary diversity
  • Job fit: How well answers align with the role requirements and rubric criteria

Custom Evaluation Rubrics

Every company evaluates candidates differently. A logistics company cares about reliability and physical stamina. A tech company cares about problem-solving and communication. Our rubric system lets you define weighted criteria — and the AI scores every candidate against your specific requirements, not a generic template.

Rubrics are AI-generated from a plain English description of what you're looking for, then refined through a chat interface. Each criterion has 5 scoring levels (Excellent to Poor) with detailed descriptions.

The Outcome

Recruiters using Sluble's AI interviewer report spending 70% less time on first-round screening. Candidates report a more consistent, fair experience. And the quality of candidates who make it to human interviews is significantly higher — because the AI has already filtered for the criteria that matter most.

Want to see this in action?

Book a 30-minute demo and we'll walk you through exactly how Sluble works for your team.

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