UIUC Computer Science · Alibaba Accio

Yuchen (Ean) Wang

I work on agentic post-training and the systems that make it practical.

I am an M.S. student in Computer Science at the University of Illinois Urbana-Champaign and a research intern with Alibaba's Accio team. Previously, I studied artificial intelligence at Peking University in the Zhi Class.

My work spans long-horizon tool use, reinforcement learning, and efficient training and inference. I also study how to schedule and accelerate video generation.

Selected research

All projects

Accio team · 2026

Occamy-1.0: Open Pareto-frontier 35B Intelligence for Co-work

Core contributor to Occamy-1.0 across agentic post-training algorithms, training infrastructure, and data: staged SFT/HDPO, model soup and SAO, compaction-aware credit assignment, execution-grounded data synthesis, and multi-harness asynchronous training.

The released model scores 82.2 on Claw-Eval and 27.6% on AutomationBench, up from 69.5 and 7.5% for the base model.

Open-source engineering

All contributions

Selected work on training data, numerical correctness, GPU memory, and runtime reliability.

vllm-projectvLLM

Halved peak memory during BF16 MoE weight conversion.

Implementation notes

In-place FlashInfer conversion reduced peak allocation from 7.88 to 3.94 GiB in the TP2 measurement, avoiding a second full set of converted weights.

huggingfaceHugging Face Datasets

Restored worker parallelism in shuffled streaming datasets.

Implementation notes

Preserved source shards through interleaving so four DataLoader workers can use 19 shards, with deterministic epoch and checkpoint regression coverage.

modelscopemcore-bridge

Improved packed QSA selection and low-precision training behavior.

Implementation notes

Scoring QSA blocks within each document was 2.70× faster in an 8K synthetic selector case. Follow-up PRs preserve BF16/FP16 gate rounding and bound PLE backward's extra workspace; full-model gains are not claimed.

NVIDIA-NeMoNeMo RL

Reduced teacher-payload transfer overhead for distillation.

Implementation notes

Deferred top-k teacher payloads across Ray workers, with a 4.44–5.31× speedup in controlled transfer measurements—not an end-to-end training speedup.

NVIDIA-NeMoMegatron Bridge

Building Bridge-local Qwen4-Exp text-decoder support.

Implementation notes

Covers QSA, per-layer embeddings, gated residuals, and HF conversion. CPU unit checks passed; GPU integration and end-to-end training parity remain pending.

flashinfer-aiFlashInfer

Corrected K/V calibration scales in ragged FP8 prefill.

Implementation notes

Applied calibration scales in the ragged prefill path so FP8 key/value tensors retain the intended numerical interpretation.

NVIDIAMegatron-LM

Fused GatedDeltaNet normalization; added selective Mamba recompute.

Implementation notes

Folded Q/K L2 normalization into the gated-delta kernel and added a selective recompute option for Mamba blocks.

NVIDIA-NeMoEmerging Optimizers

Made Muon normalization scale-invariant for small-norm inputs.

Implementation notes

Fixed the Newton–Schulz normalization path to preserve scale invariance when input norms are small.

NousResearchHermes Agent

Improved tool-schema handling and SSH reconnect reliability.

Implementation notes

Resolved local schema references during tool-argument coercion and waited for pooled SSH teardown before reconnecting.

PR status snapshot: . Live discussion on GitHub.

Engineering notes and validation details

Academic service

Reviewer, WSDM 2027.

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