Ph.D. Candidate in Computer Science, National University of Singapore · Jan 2023 – Jan 2027
yannis.montreuil@u.nus.edu ·
Google Scholar ·
GitHub ·
LinkedIn
Research Profile
I develop statistical learning theory and algorithms for reliable, cost-aware AI systems that decide when to answer
directly and when to delegate to stronger models, tools, or experts. My research studies learning-to-defer, model
routing, and multi-expert allocation, with guarantees under accuracy, cost, robustness, online adaptation, and
distribution-shift constraints.
I expect to complete my PhD in January 2027. I am looking for research internships in quantitative research and
machine learning research, and I am open to full-time roles.
Publications
Peer-reviewed
- Why Ask One When You Can Ask k? Learning-to-Defer to the Top-k Experts. Yannis Montreuil, Axel Carlier, Lai Xing Ng, Wei Tsang Ooi. ICLR 2026. arXiv:2504.12988
- Online Learning-to-Defer with Varying Experts. Yannis Montreuil*, Dang Hoang Duy*, Maxime Meyer*, Axel Carlier, Lai Xing Ng, Wei Tsang Ooi. AISTATS 2026. arXiv:2605.12340
- Adversarial Robustness in One-Stage Learning-to-Defer. Yannis Montreuil*, Letian Yu*, Axel Carlier, Lai Xing Ng, Wei Tsang Ooi. AISTATS 2026. arXiv:2510.10988
- Optimal Query Allocation in Extractive QA with LLMs: A Learning-to-Defer Framework with Theoretical Guarantees. Yannis Montreuil*, Yeo Shu Heng*, Axel Carlier, Lai Xing Ng, Wei Tsang Ooi. AISTATS 2026. arXiv:2410.15761
- Adversarial Robustness in Two-Stage Learning-to-Defer: Algorithms and Guarantees. Yannis Montreuil, Axel Carlier, Lai Xing Ng, Wei Tsang Ooi. ICML 2025. arXiv:2502.01027
- A Two-Stage Learning-to-Defer Approach for Multi-Task Learning. Yannis Montreuil*, Yeo Shu Heng*, Axel Carlier, Lai Xing Ng, Wei Tsang Ooi. ICML 2025. arXiv:2410.15729
- Towards Robust Human–AI Decision-Making via Learning-to-Defer. Yannis Montreuil. AAAI-26 Doctoral Consortium.
Preprints
- Beyond Augmented-Action Surrogates for Multi-Expert Learning-to-Defer. Yannis Montreuil, Axel Carlier, Lai Xing Ng, Wei Tsang Ooi. arXiv:2604.09414
- Learning-to-Defer with Expert-Conditioned Advice. Yannis Montreuil, Leina Montreuil, Axel Carlier, Lai Xing Ng, Wei Tsang Ooi. arXiv:2603.14324
- Learning to Defer in Non-Stationary Time Series via Switching State-Space Models. Yannis Montreuil*, Letian Yu*, Axel Carlier, Lai Xing Ng, Wei Tsang Ooi. arXiv:2601.22538
* indicates equal contribution.
Research Experience
National University of Singapore — Doctoral Researcher, Computer Science
Singapore · Jan 2023 – Jan 2027
- First-author research on learning-to-defer, model routing, expert allocation, online learning, and robustness.
- Algorithms and guarantees for deciding when lightweight predictors should act directly or delegate to stronger experts or models.
- Analysis of deferral policies under cost constraints, adversarial perturbations, non-stationarity, and changing expert availability.
- PyTorch pipelines for deferral algorithms, LLM evaluation, and distributed experiments.
CNRS, French National Centre for Scientific Research — Research Associate
Singapore · Oct 2022 – Jan 2023
- Theoretical frameworks for routing and deferral in decision-making systems under uncertainty.
- Allocation and delegation policies with guarantees for hybrid AI systems and smart-city decision pipelines.
- Collaborated with Prof. Wei Tsang Ooi, Prof. Axel Carlier, and Dr. Lai Xing Ng.
CEA, French Alternative Energies and Atomic Energy Commission — Research Intern
Saclay, France · Mar 2022 – Sep 2022
- Deep-learning and geometric methods for 6-DoF robotic manipulation of deformable objects.
- Self-supervised and implicit-learning pipelines for 3D point-cloud data.
ONERA, The French Aerospace Lab — Research Intern
Palaiseau, France · May 2021 – Aug 2021
- Improved building detection in satellite imagery using semi-supervised learning, including Mean Teacher and Naive Student.
- Increased detection accuracy by 30% through data augmentation, architectural refinements, and hyperparameter tuning.
Education
National University of Singapore — Ph.D. in Computer Science
Singapore · Jan 2023 – Jan 2027
A*STAR Merit Award; AISG–DesCartes Joint Excellence Scholarship. Research focus: statistical learning theory,
learning-to-defer, model routing, online learning, robustness, and multi-expert systems.
Arts et Métiers — M.Sc. in Industrial Engineering and Operations Research, Highest Honors
Paris, France · Sep 2019 – Sep 2022
Sorbonne University — M.Sc. in Robotics, Honors
Paris, France · Sep 2021 – Sep 2022
Sorbonne University — B.Sc. in Mechanical Engineering
Paris, France · Sep 2015 – Jun 2019
Awards
Research Achievement Award — for significant research achievements
NUS · Jan 2026
AI Singapore PhD Fellowship — AISG–DesCartes Joint Excellence Scholarship, awarded through one of Singapore's most selective national AI research scholarship programmes
AI Singapore · 2023
A*STAR Merit Award — national research merit award supporting doctoral study
A*STAR · 2023
Research Incentive Award — for strong academic standing and research progress
NUS · Jun 2023
Outstanding Academic Achievement Award — recognized among the top students
Arts et Métiers · Jan 2021
Academic Service
Reviewer: ICML 2026 (Silver Reviewer), ICLR 2026, AISTATS 2026.
Teaching: CS5242 Neural Networks and Deep Learning; CP2107 Independent Introduction to CS Research.
Students supervised: Yeo Shu Heng, Dang Hoang Duy, Letian Yu, Seah Min-Rei.
Technical Skills
| Theory | Statistical learning theory, online learning, robustness, optimization, probability, inference. |
| Research areas | Learning-to-defer, selective prediction, model routing, expert allocation, multi-expert systems, decision-making under uncertainty. |
| Methods | Formal proofs, algorithm design, regret and generalization analysis, experimental evaluation, scientific writing. |
| ML engineering | PyTorch, distributed training, LLM evaluation, large-scale ML experimentation, supervised learning, semi-supervised learning, deep learning. |
| Optimization tools | MOSEK, convex optimization, numerical optimization, Python scientific stack, C, R. |
| Languages | French (native), English (fluent), Spanish (intermediate). |
| Interests | Muay Thai, tennis, table tennis, League of Legends when I find the time. |