LLM Post-Training & Agents Research Engineer

Kaon (prev. FlowGPT); San Francisco (CA); On-site; USD 200,000 - 500,000; Full time

Job summary

Kaon, based in the San Francisco Bay Area, is seeking a Research Engineer to advance the models behind our interactive storytelling and character experiences. You will focus on post-training methods to boost model behavior and deploy capable agents with memory, tools, and long-horizon interactions.

In this role, you will build training pipelines (SFT, DPO, GRPO), craft datasets, design reward models, and evaluate improvements through offline tests and live experiments, collaborating with

Qualifications

• Experience training or post-training large language models, including RL or preference optimization.
• Ability to turn open-ended research problems into clear hypotheses, experiments, and measurable results.
• Strong Python and software engineering fundamentals; C/C++ is a plus.

Responsibilities

• Build and refine LLM post-training pipelines (SFT, DPO, GRPO).
• Develop training and preference datasets with held-out evaluations.
• Design reward models for narrative quality, memory, and personalization.
• Create agent training environments and evaluations for tool use and memory.
• Collaborate with engineering and product teams to bring improvements into production.
• Conduct offline evaluations and online A/B tests.

Skills

Python

C/C++

Post-training LLMs

RL/Pref optimization

LLM-based agents

Hypothesis testing

Ownership

Tools

PyTorch

TensorFlow

Linux/UNIX

Job description

Kaon, based in the San Francisco Bay Area, is seeking a Research Engineer to advance the models behind our interactive storytelling and character experiences. You will focus on post-training methods to boost model behavior and deploy capable agents with memory, tools, and long-horizon interactions.

In this role, you will build training pipelines (SFT, DPO, GRPO), craft datasets, design reward models, and evaluate improvements through offline tests and live experiments, collaborating with