Eigenstate

Jason Shen / Singapore

I build trading infrastructure and tools for working with AI.

In trading, sending an order and knowing what actually filled are different problems. I work on the systems that keep track of that difference.

I also build Battuta, a tool for editing music with an AI agent. The agent reads and changes MIDI files; I listen and decide what to try next. I write about what these systems get wrong and how I work through it.

More about me →

Recent writing

The check passed because it never saw the edit

A MIDI editor’s first event-order check missed a known defect because the broken edit never registered for checking. Fixing that blind spot exposed the separate limits of placement and target-selection tests.

Essay Draft

The systems behind the writing

These pages explain what each system does, the decisions behind it, and what is available to inspect.

Trading Infrastructure

Systems that track an order from the position a strategy wants to the fills its provider confirms, and show the operator when those records disagree.

proof artifact v1 · Static replay, no live trading

How it works →

Battuta

A command-line MIDI editor for working on music with an AI agent. The agent inspects notes, writes an edit request, compares the files, and plays the result. The human listens and decides whether to keep the change.

v0.1.2 — published crate · Active development and self-use

How it works →

Open the Lab to step through a trading order, a partial fill, and the difference left to reconcile.

Continue the conversation

If something here connects with a problem you are working on, I would like to hear about it.

Get in touch →