About the company
Retell AI is using first-principles thinking to reimagine the call center with cutting-edge voice AI. Thousands of companies now use Retell's AI voice agents to handle sales, support, and logistics calls that once required large teams of human agents. Backed by Y Combinator, Alt Capital, and other leading investors, we've scaled to $80M in ARR with a team of 50, up from $5M at the start of 2025, and are now valued at over $1.5B.
Responsibilities
- Define requirements and own the end-to-end pipeline for creating high-quality datasets for voice agent use cases, across both text and audio modalities.
- Engineer web-scale data pipelines and apply synthetic generation techniques to produce high-quality training and evaluation data.
- Coordinate and manage a human annotation workforce: author guidelines, define quality targets, and QA annotator output.
- Build data processing and cleaning pipelines that align datasets to production needs, balancing coverage across use cases, languages, and domains.
- Analyze production logs, curated datasets, and other sources to surface failure patterns and identify high-leverage areas for targeted data collection.
- Apply your linguistic taste to judge which outputs are more natural, conversational, and humanlike, and produce preference data that encodes that judgment.
- Partner with researchers and engineers to drive each modeling iteration.
Requirements
- 2+ years of experience in computational linguistics, language data processing, or a similar field, including hands-on work with large-scale text and audio datasets.
- Highly technical: fluent at writing scripts for data processing and at leveraging models for synthetic data generation.
- Native-level command of English, with the confidence to make opinionated linguistic calls about what sounds natural in voice agent conversations.
- You might thrive if you have a strong applied ML background in language or audio modeling — ideally having contributed to the data pipelines behind a well-known audio or language model.
- A PhD in Computational Linguistics or an equivalent field with computational emphasis.
- Experience managing human annotation and evaluation teams.
- Excitement for building scalable systems that bridge research and production.
Conditions
- Cash: 200k - 290k
- Equity: Equity Provided
- Location: Redwood City, CA, US
- US Visas: Retell AI is open to sponsoring work authorization for qualified candidates, including H1B/H-1B, TN, L-1, E-3, F-1 (OPT/CPT).
- 100% coverage for medical, dental, and vision insurance
- $70/day DoorDash credit for unlimited breakfast, lunch, dinner, and snacks
- $200/month wellness reimbursement (gym, fitness classes, etc.)
- $300/month commuter reimbursement (gas, Caltrain, etc.)
- $75/month phone bill reimbursement
- $50/month internet reimbursement