Drimva

Letta

Research Engineer / Scientist, Post-Training

San Francisco Office · Full-time · Posted Feb 4, 2025

About the job

Develops post-training methods and infrastructure to improve LLMs’ capabilities in agentic systems, including tool use, context management, and continual learning.

What you'll do

  • Train models for better agentic tool use, especially context management, and develop post-deployment weight updates that avoid catastrophic forgetting.
  • Design experiments on data mixtures, training algorithms, and models; build infrastructure for large-scale synthetic data generation and collection.
  • Create evaluations for agentic capabilities and publish research through papers, technical reports, blog posts, and open-source code.

What they ask for

  • Proficiency in Python and deep learning frameworks such as PyTorch.
  • Expertise in post-training methods, such as SFT fine-tuning, reinforcement learning, reward models, or preference learning.
  • Ability to balance execution speed with empirical rigor.
  • Proven impactful research track record and real-world impact beyond academic work.

Tools

Python, PyTorch

AI focus

Post-training LLMs for agentic tool use and context management; continual post-deployment learning without catastrophic forgetting; synthetic data and agentic evaluations.

Model-written summary · the original posting is authoritative

First seen Oct 10, 2026 · Last verified Nov 5, 2026 (UTC)