Daisy Xinlei Lin

Daisy Xinlei Lin

Research brain. Builder hands.

Research Scientist & Engineer, Amazon AGI SF Lab

I build zero-to-one SFT/RL recipes for frontier agents: identify failure modes, turn them into targeted data and environments, design evaluations, and debug production-scale training until it learns stably. I own this process for a 100B mixture-of-experts coding agent, raising Terminal-Bench 2.0 to 45% and reaching 70% on SWE-bench Verified, outperforming leading open-weight baselines. Previously, I built and shipped Nova Act’s zero-to-one RL recipe—including algorithm experiments, environment scoping, online data curation, and fixes for reward collapse and train–inference mismatch. Nova Act launched with state-of-the-art performance on REAL Bench and WorkArena. I enjoy driving a research agenda, from choosing the right problems to carrying long-running work through to impact. Across both projects, my favorite part is finding the failure no one can quite name yet, making it measurable, and building the training system that fixes it.

My PhD at NYU was about how humans plan and learn: I ran large-scale experiments to understand what makes people get better at complex tasks, and how that compares to AI.

I think AI should be humans' thought partners, adapting to collaborate with us better and better.

For fun, I explore new interaction paradigms for human-AI collaboration: tools that adapt to how you think, not the other way around.

  • The point of building AI isn't to think for us. It's to leave us more room to think.
  • My entire PhD could be done in two months with the tools we have today. What took years wasn't the work; it was learning to ask the right question, and no tool has automated that yet.
  • Women are run by hormones more than anyone admits, and some weeks I'm a genuinely different person. Learning to work with that rhythm instead of against it was one of the more useful things I ever figured out.
  • I stopped believing in most of my own limits after walking 46 miles in Patagonia (sick on day 3, recover overnight, keep going) and running the NYC Marathon in 2024 on almost no training. The body's ceiling is much higher than the mind's estimate of it.
  • Making something you can hold, like ceramics or tiramisu, after months of only making things in code is satisfying in a way I still can't fully explain. I think the hands know something the screen doesn't.
  • Everything in moderation, including moderation.

I snowboard when I can (Hokkaido is the dream), bake when I need to think, make ceramics, and am currently being managed by two cats named Boba and Milk who take their supervisory roles extremely seriously.

Currently deep in: Japanese ceramics, reward models, and the correct ratio of mascarpone to cream.