Ruei-Shi Tuo

Senior Java Engineer · Low-latency systems · New York

I'm a senior Java engineer in New York, working on low-latency trading infrastructure and high-throughput post-trade systems. I spent a decade at Barclays building post-trade platforms for securities settlement and payments, and earlier roles at Credit Suisse, Bank of America, Morgan Stanley, Markit, and Citigroup. I'm currently building independently.

This site is where I write about that work. Posts fall into two categories. Technical notebooks are long-form pieces working through specific engineering problems — deterministic execution, zero-GC Java, lock-free concurrency, mechanical sympathy. Industry notes are shorter pieces about capital markets technology and the parts of the field that don't get written about often enough.

Two ideas run through everything here. Do one thing, and do that one thing perfectly — not out of narrow-mindedness, but as a discipline of finding the true boundary, isolating it, and owning every microsecond of its latency budget. And: question whether the problem needs solving — or just removing.

Engineering an Institutional High-Frequency Trading System

Deterministic straight-through processing, kernel-bypass networking, and what production-grade actually means.

The Pragmatic Engineer's Guide to Low-Latency Java

Mechanical sympathy, CPU cache optimization, and JVM tuning for trading systems.

All writing →

NitroJ Exchange

Institutional HFT matching engine. Zero-GC, lock-free, Aeron-based messaging.

Crypto Market Data Gateway

Multi-exchange market data infrastructure. Netty WebSocket clients, SBE and FlatBuffers serialization.