Xiyuan (Tommy) Guo

Systems | Software Engineer

Architecting high-performance systems and low-latency terminal architecture for power users.

I’m a software engineer focused on the intersection of quantitative finance and distributed systems. I specialize in building high-performance Svelte applications that bridge the gap between complex backend logic and intuitive, low-latency user interfaces.

Currently, I am focused on architecting terminal-centric tooling and reactive web systems, notably as the creator of difi and zsweep (HN #5 & #6). Beyond my own projects, I am an Open Source Contributor to Neovim and Statue. I’m also deep-diving into market microstructure—working through The Green Book to apply systems engineering rigor to quantitative finance.

When I’m not at the terminal, you can usually find me at the Muay Thai gym, training calisthenics, or behind a drum kit. I’m an avid off-roader in my Tacoma TRD Pro and a heavy consumer of specialty coffee. I am currently completing my double major in Physics and Computer Science (Expected May 2028) at the University of Virginia.

Experience

APR 2026 — PRESENT

Research Assistant · UVA (BAL Lab)

Formulating a quantum-inspired psychometric framework utilizing Hilbert-space probability models to map how individuals transition from cognitive uncertainty to commitment across repeated longitudinal measurements. Engineering a multivariate longitudinal missing data imputation framework that enforces the Law of Total Variation, with a custom Lagrange-constrained C++17 gradient descent solver implemented via RcppArmadillo.

  • C++
  • RcppArmadillo
  • Psychometrics
  • Optimization
  • Mathematical Statistics
FEB 2026 — PRESENT

Research Assistant · Yale (Liu's Group)

Developing a deep unrolled ADMM framework for blind computational polarimetry, reconstructing the full Stokes polarization cube from single diffuser speckle measurements. Engineering a custom PyTorch U-Net pipeline with rigorous physics-informed constraints using vectorial Stokes parameter representations and Lorentz cone orthogonal projections, yielding 4.5 dB PSNR improvement over baseline methods.

  • PyTorch
  • ADMM
  • Computational Imaging
  • Physics-Informed Neural Networks
  • Polarimetry
OCT 2025 — PRESENT

Research Assistant · UVA (Ke's Group)

Applying quantum mechanics principles to engineer Density Functional Theory (DFT) and Dynamical Mean-Field Theory (DMFT) reconstruction algorithms for frontier rare-earth materials research. Architecting a cloud-native ML pipeline using Go and Next.js backed by DOE-BES and DOE-ARPA-E funding, and creating immersive browser-based 3D atomic visualizations with Three.js and JSmol.

  • Go
  • Next.js
  • DFT
  • Three.js
  • Quantum Mechanics
  • Machine Learning
MAY 2026 — PRESENT

Research Intern · UVA Biocomplexity Institute

Formulating massive-scale network simulations modeling stochastic viral pathogen spread via SEIR compartmental cascade models. Engineering attention-based Graph Neural Network (GNN) architectures to predict multi-hop epidemic propagation using spatiotemporal message-passing frameworks on HPC infrastructure.

  • GNN
  • Network Science
  • Simulation
  • Bayesian Data Science
  • HPC

Projects

smriti — Longitudinal Imputation Engine preview

smriti — Longitudinal Imputation Engine

An R package for automated longitudinal missing data imputation. Executes a three-phase architecture combining missForest initialization with a custom C++ Lagrangian projection engine to strictly preserve the structural variance of the target covariance manifold.

  • R
  • C++
  • RcppArmadillo
  • Statistics
  • CRAN
difi — Git Diff Review Tool preview

difi — Git Diff Review Tool

A high-performance CLI tool built in Go for interactive Git diff reviews. Features a keyboard-centric Terminal User Interface (TUI) with a file tree and editor-aware navigation, allowing users to jump directly to specific lines in Neovim/Vim for rapid code refinement.

Y HN #6
342
  • Go
  • Bubble Tea
  • Git API
  • CLI
  • Nvim Plugin
sanjaya — Academic Graph Pipeline preview

sanjaya — Academic Graph Pipeline

An automated academic literature extraction pipeline utilizing the OpenAlex Academic Graph API, Scrapy, and Playwright. Extracts bilingual data and exports structured CSV/JSON datasets for downstream interdisciplinary research applications.

  • Python
  • Scrapy
  • Playwright
  • Data Engineering
  • Academic Graph
Neovim — Contributor preview

Neovim — Contributor

Contributed multiple Pull Requests to the Neovim core (C/Lua). Focused on Lua state change and ENV variable config supporting Vim logic.

90k+
  • C
  • Lua
  • Open Source
  • Systems

Certifications

Loosely designed in Figma and engineered in Neovim on an HHKB. Built with SvelteKit and Tailwind CSS, reviewed with difi, and deployed with Vercel.