Research Engineer, Production Model Post-Training

Overview

Research Engineer on Anthropic’s Post-Training team, training base models through the post-training stack to deliver production Claude models.

What you'll do

• Implement and optimize post-training techniques at scale on frontier models.
• Conduct research to develop and optimize post-training recipes that improve production model quality.
• Design, build, and run pipelines for model fine-tuning and evaluation.
• Develop tools to measure and improve model performance across multiple dimensions.
• Translate emerging techniques into production-ready implementations with research teams.
• Debug complex issues in training pipelines and model behavior.
• Establish best practices for reliable, reproducible post-training.

What you'll need

• Proficiency in Python.
• Experience building complex ML systems.
• Comfort working with large-scale distributed systems and high-performance computing.
• Experience with training, fine-tuning, or evaluating large language models.
• Strong software engineering skills for ML systems.

Details

• Interviews are conducted in Python.
• May require responding to incidents on short notice, including weekends.
• Location-based hybrid policy: expected in an office at least 25% of the time.
• Visa sponsorship is available for this role (not guaranteed for every candidate).