Sierra
Research Engineer, Applied Research
San Francisco, CA · On-site · Full-time · Posted Oct 5, 2026
- Education
- A degree in computer science, machine learning, or a related field, or equivalent professional experience.
About the job
Develop and deploy models and evaluations that improve Sierra’s customer-facing AI agents, advancing applied research in post-training, voice AI, and long-horizon task execution.
What you'll do
- Frame customer and product problems as machine-learning tasks, then develop, fine-tune, evaluate, and deploy models.
- Advance post-training methods and build evaluations that connect model performance to real-world agent quality.
- Work with large-scale text and audio datasets, taking research and experiments through production deployment.
What they ask for
- Strong experience building and deploying production machine-learning and AI systems.
- Experience working deeply with data, experimentation, evaluation, and model iteration.
- A degree in computer science, machine learning, or a related field, or equivalent professional experience.
Nice to have
- Experience with supervised fine-tuning or reinforcement learning.
- Experience training and deploying language, speech, or multimodal models.
AI focus
Applied AI and ML research for customer-facing agents, including post-training, voice AI, long-horizon task execution, and model evaluation.
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