Systems Engineering for Automated Trading

Automated trading systems that a human can monitor and stop.

Termondt Tech builds the infrastructure behind a systematic trading operation: market data, decision support, automated execution and risk controls, with hard safety rails in place from the first day. In 2026 I guided an AI coding agent to build and run one against a real brokerage account, then shut its first strategy down on the evidence. The write-up is public, including what went wrong.

Get in touch Read the Argus story

A status page for the Argus trading system beside a phone showing a red halt button: session open, reconcile clean, one position watched every five seconds, kill switch not engaged, audit log chain verified; below, four hash-chained audit records linked in sequence.

What I build

One problem, worked deeply: infrastructure precise enough to run a live trading operation automatically, and transparent enough that a person can see what it is doing and stop it.

Market data and decision support

Pipelines that take in live market data, score opportunities against a defined strategy, and put ranked, explained decisions in front of a person. Built to support judgment, not replace it.

  • Real-time data pipelines and broker integrations
  • Signal engines that write every decision to an audit log
  • Status pages and alerts a person can read on a phone

Automated execution and risk controls

Systems that place, watch and close trades by rule, with the rails that make that safe: one place in the code that can send an order, limits enforced twice, and a kill switch that halts new risk without abandoning the positions it is protecting.

  • Kill switches, loss breakers and fail-closed halts
  • Reconciliation against the broker before anything resumes
  • Invariants pinned by tests that read the source

Monitoring and operational reliability

The part that keeps an automated system honest: a hash-chained audit trail, continuous reconciliation, and alerting that fires when something is wrong, including when the thing that is wrong is silence.

  • Hash-chained audit logs with one enforced writer
  • Continuous reconciliation against the source of truth
  • Staged rollout: shadow, sandbox, then live at minimum size

Two ways to work with me

Both come from the same fourteen weeks and the same fourteen years.

Rails Review

Two weeks. For teams putting AI-written code into production.

I read your agents' prompts, their output and your tests, and hand back the two things most AI-built systems are missing: a written constitution, the rules the agent has to obey no matter what it is asked, each with its reason, and the pinned invariants, tests that prove the dangerous thing cannot happen anywhere in the code.

Ask about a Rails Review

Trading infrastructure, built and operated

For a trading or investment operation that needs execution, risk controls or reconciliation.

Built to run automatically, and to be monitored and stopped by a human. That is what I did for fourteen years at the New York Stock Exchange and Chicago Trading Company, and what Argus is: a platform that went from first commit to a real brokerage account in nine weeks, under rails that held when the strategy did not.

Talk about a build

How I build

The same loop whether the code is written by me or by an AI agent I am directing. Most of the work is in the first step and the last.

Specify

What the system must do and must never do, each "never" with the reason it exists. The rules file is read before any code is touched, every time.

Build

Design first, naming the alternatives rejected. Sign-off before implementation. Then code, tests, and a review of the build against the design.

Prove

Shadow, then the broker's sandbox, then live at the smallest size allowed. Research is pre-registered: the questions and the stopping rule are committed before the data is seen.

Operate

Deployed under a status page, alerts, and a kill switch reachable from a phone. Every incident becomes a rule, and every rule becomes a mechanism.

The evidence

Argus, July to October 2026. Written by an AI agent under my direction and review, run against real money at minimum size, and documented as it went.

435

commits in 14 weeks

3,540

tests

87

decision records

741

lines of rules the agent reads first

1

strategy shut down on the evidence

Part one

I guided an AI to build and run a live trading desk. Here is what it took to make that safe.

The constitution, the kill switch that forgot it was pressed, the day the agent opened the live database, and ten rules for a CTO letting AI write software that can hurt them.

Part two

How a strategy earns capital: the research platform behind Argus

Four commits in a fixed order, one look at the held-out period, nine predictions that all came true, and a strategy that still did not pay. How to know you are not fooling yourself.

How I operate

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Automated and watched

Fully automated systems that a human can monitor and stop, in one action, from a phone
✅

25 years in trading infrastructure

Order-entry gateways at the New York Stock Exchange; market connectivity, FPGA and DevOps at Chicago Trading Company
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Narrow, deep focus

A small number of systems, built and operated deeply rather than spread thin
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Evidence over spin

The first strategy lost money and was stopped. The write-up says so, with the numbers

Get in touch

If your team is putting AI-written code into production, or you run a trading operation that needs execution, risk controls or reconciliation built to run automatically, use the contact form and tell me what you are running.