The position didn’t change. Did the button work?
A trading demo needed to show why rereading a trade left the holding unchanged, then guide readers through the rest of the order.
Note Draft
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
My tool’s instructions hid a feature it already had
Battuta’s instructions discouraged edits the tool already supported. Checking its command help against the parser catches missing and invented operation names.
Note Draft
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 distinguish the position a strategy wants, the trades a provider records, and the fills entered in the internal books.
Public material: interactive teaching example · Constructed example, 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 follow a buy order through recovery and completion, or compare two MIDI edits by ear.
Continue the conversation
If something here connects with a problem you are working on, I would like to hear about it.
Get in touch →