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Job listing

San Francisco, United States$180K-$250K + Equity

Research Scientist, Post-Training at fast-growing conversational AI startup

Are you ready to redefine how humans interact with technology? This venture-backed startup in San Francisco is looking for a Research Scientist to lead post-training efforts for a next-generation speech-to-speech AI platform. You will work on 10B+ parameter models and 100+ TBs of data to create fluid, emotionally intelligent voice interactions that feel truly human. With a founding team backed by top-tier VCs, significant equity on the table, and an aggressive ship-to-production culture, this is a rare opportunity to bridge the gap between deep research and real-world impact. If you have PhD-level expertise in RLHF or LLM alignment, this is the role for you.

Overview

Role overview

You will drive model alignment and performance for next-generation speech-to-speech AI. This role involves hands-on research, data curation, and executing training experiments using RLHF and SFT to improve emotional intelligence in dialogue. You will work with large-scale models and massive datasets to bridge the gap between transactional exchanges and natural, human-like conversations.

Company

About the company

Fast-growing conversational AI startup

Responsibilities

What you will do

  • Lead post-training workflows including supervised fine-tuning (SFT) and preference optimization (RLHF/DPO) for large-scale models.
  • Curate high-quality datasets and design automated or human-in-the-loop evaluation frameworks to measure model performance.
  • Formulate and test hypotheses to improve model alignment, emotional context, and real-time dialogue management.

Candidate profile

Who this is a fit for

  • PhD in Machine Learning or related field with publications at top-tier conferences like NeurIPS or ICML.
  • Hands-on experience training 1B+ parameter models, specifically in LLM post-training or state-of-the-art speech modeling.
  • Proven ability to thrive in early-stage environments with a focus on shipping fast and obsessing over user experience.

What makes it remarkable

Why this role is remarkable

  • Work on cutting-edge duplex AI architectures that move beyond traditional walkie-talkie style voice interactions.
  • Join a mission-driven founding team backed by top-tier VCs and prominent technology industry leaders.
  • Significant equity and high autonomy in an environment designed for rapid iteration and shipping research to production.

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Jill
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