Simon Yu

You can also call me U Chi Lok (余知樂) or Simão (in Portuguese)

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I am a 3rd year PhD student at Northeastern University, advised by Weiyan Shi. My research goal is to build self-improving agent systems via self-play and interaction with real-world feedback. I closely work with Chris Manning from Stanford and Natasha Jaques from UW. I am currently interning at MSR Redmond with Baolin Peng and Jianfeng Gao, working on AI for AI and self-improvement. Before that, I interned at Orby AI, mentored by Peng Qi.

I work toward this goal from three angles:

  1. Self-Play and RSI: enabling agents to improve through self-play and build their own training environments (AutoEnvScaling for automating the data flywheel; SPADE for self-play in generated environments; SCOPE for population co-training for user simulator; SPIRAL for reasoning through zero-sum games).
  2. Meta-Agents: Shepherd turns an agent’s execution into a reversible, Git-like trace, so meta-agents can inspect, fork, replay, and revert other agents’ runs to supervise, optimize, and train them.
  3. Environment Scaling & Continual Learning: scaling what agents learn from and what they keep, including TextArena for multi-agent environments and evaluation, GEM for unified, scalable environment generation, and PolySkill for continually aggregating experience across new domains.

One of the most influential lessons to me is from The Bitter Lesson by Richard Sutton and The Era of Experience by David Silver and Richard Sutton. The idea is not just limited to AI but can be applied to any choice in life. Always choose the path that benefits in the long run, instead of the path that might be easier in the short run.

news

Sep 28, 2026 Talks on Shepherd at FAR.AI / CBAI (CAIRD Workshop), Tencent, and Apple.
Sep 24, 2026 Two papers Shepherd and Coding with “Enemy” accepted at NeurIPS 2026.
Aug 20, 2026 SCOPE accepted at EMNLP 2026 (Main).
Jul 14, 2026 Co-organizing the Managing Agents that Manage Agents workshop at NeurIPS 2026.
Jul 11, 2026 Coding with “Enemy” received the Best Paper Award at the DL4C Workshop at ICML 2026.

posts

selected publications

  1. Arxiv
    Leon Guertler , Bobby Cheng , Simon Yu, Bo Liu, Leshem Choshen , and Cheston Tan
    In , 2025