I build AI infrastructure for large-scale LLM training, focusing on hybrid parallelism, performance modelling and automated strategy planning. I received my PhD in Computer Science from Sorbonne Université in July 2026, with doctoral research at EURECOM and Huawei Paris through the CIFRE programme.
This research led to planners now integrated into MindSpore and MindFormers. The systems have been evaluated on dense, mixture-of-experts (MoE) and multimodal models. Across these projects, experiments span Ascend-910 clusters with up to 16,384 NPUs and models with over 1T parameters. This work has also supported production training, including China Telecom’s DeepSeek-MoE deployment and TeleChat3-MoE. See the systems and publications below.
Research focus
How a model is partitioned and scheduled across accelerators affects training time, memory use and cost. Choosing a parallelisation strategy often requires extensive profiling and manual tuning for each model and cluster.
How can we plan parallelism for large-scale training without per-cluster profiling, while retaining portability across models and hardware?
I develop analytical cost models and optimisation methods to estimate the performance and memory requirements of a training strategy before execution. The systems below address memory prediction, pipeline scheduling, joint optimisation, incremental re-planning and user-specified constraints.
Publications
Selected Systems & Publications
Concord
NeurIPS 2026 · Accepted
Can Hybrid-Parallel Planning Support Alternating Model–Strategy Design?Dependency-Keyed Per-Layer Primitives for Re-Planning.
Ruiwen Wang, Thibaut Tachon, Raja Appuswamy, Chong Li.
Reuses per-layer primitives during hybrid-parallel re-planning, recomputing only those affected by a model edit.
Median re-planning speedup of ~2.7× across audited model edits, with provably identical plan selection to a full search; evaluated on dense and MoE models using up to 4,096 NPUs.
PRISM
SCA / HPCAsia 2026
PRISM: Profiling-Free Symbolic Memory-Driven Strategy Planner for Large DNN Model Training.
Ruiwen Wang, Philippe Fang, Chong Li, Thibaut Tachon, Raja Appuswamy.
Osaka, Japan · Jan 26–29, 2026
Plans hybrid-parallel training without profiling, using symbolic memory models, estimates that account for recomputation, and topology-aware communication costs.
92–96% memory prediction accuracy (median error ≈ 7%) across DeepSeek3, Llama2-3, Mistral, TextHawk and Llama-MoE on up to 1,024 Ascend-910 NPUs; up to 1.43× the model FLOPs utilisation (MFU) of Megatron-LM.
BMPipe: Bubble-Memory Co-optimization Strategy Planner for Very-Large DNN Training.
Ruiwen Wang, Chong Li, Thibaut Tachon, Raja Appuswamy, Teng Su.
27th IEEE CLUSTER · Edinburgh, UK · Sep 2–5, 2025
Uses integer linear programming (ILP) to jointly optimise pipeline execution and memory use, accounting for recomputation, load imbalance and preparation bubbles.
1.36× speedup over Megatron-Even on a 16,384-NPU Ascend-910 cluster; up to 1.70× with 1F1B-Interleave; the ILP is solved in under 200 ms at production scale.
A two-level optimiser combines symbolic cost modelling with an ILP to jointly plan hybrid-parallel configurations, layer-to-stage assignments and recomputation.
36.7% speedup over the D-Rec baseline on 128-device clusters; 35.7% MFU on DeepSeek-141B — without profiling on accelerators.
Lets users specify parallelisation strategies for selected operators, while a D-Rec-based planner determines a consistent strategy for the rest of the graph.
Up to 2.24× speedup over D-Rec on Mixtral-8×7B with expert parallelism (8 NPUs); 2.04× on Llama3-8B at 8K context; 1.45× / 1.30× on Qwen2.5-72B at 32K context (64 NPUs, combined with BMPipe).
Best Poster Award — Euro-Par 2025, Dresden · for H²O
Letter of Appreciation — China Telecom, 2025 · for deploying training optimisations for DeepSeek-MoE
Golden Prize — Huawei Challenge for Automatic Load Balancing, 2024
Experience
2023–26Huawei Paris — PhD Researcher (CIFRE) · developed compute, memory and communication cost models and planners for LLM pretraining; integrated into MindSpore and MindFormers, benchmarked against Megatron-LM and evaluated on up to 16,384 NPUs
2021–23Huawei Paris — Research Apprentice → Research Engineer · profiled and optimised LLM training and inference on Ascend-910 production clusters, with a focus on bottleneck analysis
Education
2023–26PhD in Computer Science — Sorbonne Université · EURECOM · CIFRE programme with Huawei Paris · advised by Raja Appuswamy & Chong Li · defended 24 July 2026 Thesis: Systematic and Portable Optimisation of Hybrid Parallelism for Large-Scale Distributed Training Jury: Corinne Ancourt (Mines Paris–PSL) & Gaétan Hains (UPEC), reviewers · Serge Petiton, examiner · Denis Barthou, president
2019–22MSc in Computer Science — Sorbonne Université, Paris · advised by Emmanuel Chailloux & Jacques Malenfant
2016–19BSc in Computer Science — Université Paris-Saclay · mentored by Isabelle Guyon, Viviane Pons & Zhengying Liu
Timeline
Concord accepted at NeurIPS 2026.
Defended my PhD thesis, Systematic and Portable Optimisation of Hybrid Parallelism for Large-Scale Distributed Training, at Sorbonne Université.