Joonhun Lee

I'm Joonhun Lee, an AI research team lead from 🇰🇷 for now. I'm passionate about translating research-stage ideas into deployable systems that hold up under real-world constraints, particularly in finance.

  • Decision Systems
  • Financial Intelligence
  • Agentic Workflows

Experience

Qraft Technologies

AI Research Team Lead

Leading AI research across order execution, market and asset class expansion, LLM-mediated financial signaling, and ML-driven asset allocation — translating research-stage agentic patterns into deployable decision systems under real-world constraints.

AI Researcher
Dec '23 - Dec '25

Built and deployed reinforcement learning systems for order execution and futures trading, designing policies and evaluation pipelines robust to noisy, non-stationary, and partially observable market environments.

Dec '25 - Present

Wavebridge

Quantitative Developer

Engineered trading infrastructure and quantitative research systems for digital-asset market making — supporting systematic strategy research and decision analysis under realistic execution constraints.

Sep '23 - Nov '23

Doctor Now

Chief of Staff

Drove Office of the CEO workstreams across investor relations, business development, operations, and data/product initiatives during a period of rapid growth — bridging product, data, and operations into actionable decisions.

Oct '21 - Feb '22

Education

Seoul National University

M.S. in Computational Science and Technology
Mar '22 - Feb '24

CFA Institute

Passed all three levels of the CFA Program

Seoul National University

B.S. in Physics Education
Mar '17 - Feb '22

Publications

Generalized Gaussian Temporal Difference Error for Uncertainty-aware Reinforcement Learning

Under review

Uncertainty-aware reinforcement learning has long assumed TD errors are zero-mean Gaussian, which miscalibrates how confident an agent should be in its own value estimates. A generalized-Gaussian replacement — with a learnable shape parameter governing uncertainty and a kurtosis-aware sample weighting — improves sample efficiency for both SAC and PPO across MuJoCo continuous control.

Feature-aligned N-BEATS with Sinkhorn divergence

ICLR '24 (Spotlight)

Time-series forecasters tend to collapse when the test distribution drifts — an unseen market regime, a new region's weather — because they have no mechanism for learning what is invariant across source domains. Stack-wise optimal-transport (Sinkhorn) alignment of N-BEATS feature distributions across source domains restores generalization under severe shift, while preserving the model's interpretable basis decomposition.

MINR: Implicit Neural Representations with Masked Image Modelling

ICCV '23 Workshop on OOD-CV

Masked autoencoders inherit the masking strategy they were trained on — change the mask shape or move to an out-of-distribution image and reconstruction collapses. MINR reframes masked image modeling as predicting a continuous coordinate-MLP from the visible pixels via a transformer hypernetwork, reconstructing across unseen masking patterns and OOD domains with roughly 7x fewer parameters than MAE-Large.

Hard Skills

Programming Languages & Tools
  • Python
  • SQL
  • Rust
  • Go
  • C++
  • Vyper
  • Vue.js
  • Flutter
  • Git
  • Docker
Documentation & Design
  • LaTeX
  • Markdown
  • Excel
  • PowerPoint
  • Illustrator
  • Premiere Pro
  • Figma

Organizations

MCSA (SNU Management Consulting Student Association)

Alumni

Interests

Personal Agents, Data Modeling, Mechanical Watch, Golf & Tennis