Retell AI

Research Scientist - LLM

San Francisco Bay Area

Work authorization required$225k-$400kDetected 99 days ago

Machine LearningPyTorchLLMsA/B TestingNegotiationLogisticsResearch

About the role

This is a research-driven, high-impact role for ML researchers who want to push the boundaries of real-time AI.
As a Founding Machine Learning Research Engineer at Retell, you'll focus on advancing model capabilities for human-like voice agents operating in complex, real-world environments.
Your work will directly influence production systems, bridging cutting-edge research with real-world deployment.

Research & Experimentation - Explore and develop new techniques across LLMs and audio models to improve reasoning, latency, and conversational quality in real-time systems.
Model Training - Rapidly build and iterate on models and pipelines, turning research ideas into working prototypes. Innovate on paradigms, training methods, and inference.
Evaluation & Benchmarking - Design novel evaluation frameworks, datasets, and metrics to measure performance on complex, real-world voice tasks.
Bridge Research to Production - Collaborate closely with engineering to translate research insights into deployable systems.
Human Feedback Loops - Develop methods to incorporate human evaluation into model improvement, especially for subjective conversational quality.
Let's build the future together.

Experimental Mindset - You enjoy exploring open-ended problems and iterating quickly on ideas.
Bridge Theory & Practice - You can translate research into systems that work in real-world environments.
Thousands of companies now utilize Retell's AI voice agents to handle sales, support, and logistics calls that once required large teams of human agents.

Equivalent research-level engineering experience also considered.
Published or Awarded - First/co-author publications at top-tier venues (NeurIPS, ICML, ICLR, ACL, Interspeech, etc.) or notable competition awards are a strong plus.
Top Academic Background.
Master's degree in CS, ML, AI or related field required

100% coverage for medical, dental, and vision insurance
$200/month wellness reimbursement
$300/month commuter reimbursement
$75/month phone bill reimbursement
$50/month internet reimbursement
Our vision for 2026 is to build a modern CX platform where entire contact centers are powered by AI.
Small teams, >$1M revenue/employee, significant equity
Deep Technical Foundation - Comfortable with PyTorch, model architectures, and the math behind modern machine learning.

Retell AI is open to sponsoring work authorization for qualified candidates, including H1B/H-1B, TN, L-1, E-3, F-1 (OPT/CPT), and O-1 visas.

This listing is sourced directly from Retell AI's careers page and normalized into a canonical job model.