Systems Architect · Capital Markets · Low-Latency Trading · Applied Cryptography

Seungmin Han 한승민

I architect low-latency systems from the metal up — where microseconds and correctness both matter.

Experience

Where I've built

Korea Investment Securities — Investment Engineering

September 2024 – Present

Market-Making / Liquidity-Provision (MM/LP) Systems Developer

  • Solely re-architected and fully rebuilt the desk's MM/LP system for ~5,500 instruments (futures, options, ELW, ETN) — full-stack: backtesting DB → low-latency C++/C# back-end → C# / DevExpress front-end.
  • Ported the core order logic from Windows/C# to C++20 with CPU pinning, a busy-spin event loop, lock-free queues, and a pool allocator — cut tick-to-trade latency from 5 ms to ~25 µs (200×), verified with perf-based profiling.
  • Specced and validated a network switch replacement and NIC kernel-parameter tuning with the infrastructure team, further cutting network-layer latency.
  • Implemented quoting logic for options, basket, and single-stock futures/options arbitrage strategies with the quant-trading desk — microprice-based fair-value pricing and real-time quote adjustment.

Supergate — Applied Cryptography

Summers 2022 & 2023

Software Engineer Intern → Returning Software Engineer Intern

  • Researched fully homomorphic encryption (FHE) and built a searchable FHE database library in C++ (C++ · MongoDB) supporting private exact-match queries over encrypted data.
  • Improved it with efficient private-query protocols and CRUD; implemented two novel protocols that cut query-result size ~50%, and filed two Korean patents.
  • Cross-compiled the server and sub-libraries onto a Xilinx Zynq FPGA board.

University of Pennsylvania — Teaching Assistant → Head TA

January 2022 – May 2024

CIS 5480 — Operating Systems (graduate, ~250 students)

  • Added fuzz-style automatic edge-case generation to the Python auto-grader, expanding coverage across students' C operating-system implementations.
  • Designed and taught a Linux-style OS capstone (process scheduler and file system in C); ran weekly reviews of low-level C systems code (scheduling, virtual memory, syscalls).

Karrot (Daangn) — Global Product

June 2021 – September 2021

Global Technical Product Management Intern

  • Drove 150% MAU growth for the Karrot marketplace in Toronto.
  • Built a real-time in-app behavioral dashboard (BigQuery); proposed a consumer-penetration strategy from PMF analysis.

Flagship Work · Korea Investment Securities

Systems carrying a securities firm into its next architecture

The two modernizations I lead that are moving the firm's legacy trading platform onto a faster, cleaner foundation.

Trading-Platform Re-Architecture

.NET 8 / C# · INCREMENTAL MIGRATION

A ground-up re-platforming of the firm's 13-service .NET trading monolith into independently deployable services — migrated piece by piece and verified against the old engine running in parallel, so behavior is provably preserved with no risky all-at-once cutover.

C++ Ultra-Low-Latency Order Engine

C++20 · TICK-TO-TRADE · LOCK-FREE

A from-scratch order/hedge engine — core-pinned threads, busy-spin loop, lock-free queues, pool allocator — that cut tick-to-trade latency from 5 ms to ~25 µs (200×); the basis of porting the core order logic from Windows/C# to C++20.

Independent Projects

What I build on my own time

Self-directed work at the intersection of markets, systems, and frontier tooling.

Equity Research Web System

PYTHON · MULTI-AGENT LLMs · SELF-HOSTED

A local, self-hosted multi-agent system that researches and scores equities — parallel agents gather and cross-check multi-source data, a multi-factor model scores each name, and a self-audit loop of independent agents adversarially re-grades every verdict before it surfaces in the web dashboard.

FHE Secure Voting Platform

C++ · HELIB · CRYPTOGRAPHY

An end-to-end encrypted election system where ballots are tallied entirely under encryption — so a server or DB compromise (SQL injection, exfiltration, tampering) yields only ciphertext, neutralizing whole classes of attacks. Led as senior design; won the "Most Technically Challenging" award.

GitHub →

Self-Hosted Compute & Automation Mesh

TAILSCALE · DOCKER · CRON · WAKE-ON-LAN

A private mesh — Mac orchestrator, always-on mini, and a wake-on-LAN Linux server — running scheduled data jobs and services with git-backed sync and a trace-free, reproducible deployment philosophy.

Earlier Research — ML & Cryptography

Machine-learning & cryptography work at Penn

Where the ML and cryptography interests started.

Arxiv Text Summarization

RNN · NLP

A neural-network approach to summarizing and labeling academic papers.

GitHub →

Receipt Information Extraction

DONUT · DOCUMENT AI

Document-AI extraction from receipt images with the Donut visual encoder-decoder model.

Oblivious Pseudorandom Functions

CRYPTOGRAPHY · MASTER'S THESIS

Master's thesis exploring OPRFs and their applications in privacy-preserving protocols.

Research & Education

Cryptography credentials

Patents (filed)

  • FHE-based Encrypted Index — KR 10-2023-0115045
  • FHE-based PDQ Protocol — KR 10-2023-0115051

Education

  • M.S.E., Computer & Information Science, UPenn — August 2023 – May 2024
    Thesis: Exploring Oblivious Pseudorandom Functions and their Applications
  • B.S.E., CIS + Math minor, UPenn — August 2017 – May 2023 · GPA 3.64 · Dean's List

Capabilities

What I bring

Capital Markets & Trading

Market making / LPIndex arbitrage Derivatives hedgingMarket data Exchange / FEP connectivityLow-latency execution Pre-trade risk

Cryptography & Security

FHEPrivacy-preserving protocols Applied securityCrypto / market-data systems

Engineering

C++20C# / .NET 8Python TypeScript / ReactSQL System architectureConcurrency & lock-free Distributed / real-timeFastAPI / HTMX Machine learning

Product & Business

Product managementData-driven growth Tech ↔ business translationCross-functional delivery Korean (native)English (fluent)

Let's talk

Let's build something solid.

Open to architecture, engineering, product, and business-development roles. Reach out — happy to walk through any of the work above.