Ashton Chew
Research at Long Lake
Work
I research RL and evals at Long Lake.
Previously, I was a Member of Technical Staff Intern at Amazon AGI Labs, working on RL and RL infrastructure.
Before that, I was the first Founding Engineer at Theta (YC X25), where I researched RL environments and built eval infra.
Earlier, I worked on evals as a Machine Learning Engineer Intern on Amazon AGI’s inference team.
Research
Stubborn or Sycophantic? GEPA-Evolved Prompts Under Pressure
To appear in NeurIPS 2026
WARP: A Wrapper-Based, Adaptive, Realistic Pipeline for Reliable Web-Agent Robustness Testing
ICML 2026