JAVA / GO / TYPESCRIPT / PYTHON

A trading terminal.
A system built to explain its state.

Realtime quotes, authoritative order activity, exact financial calculations and asynchronous news insights in one compact workspace.

Full stack running locally in simulated/MOCK mode.

The terminal in motion

Real application recording · simulated trading

A fresh simulated session: quotes and chart history, a buy/sell round trip, Core-calculated Day P&L, execution notifications and synthetic news insights. No live-money orders or live model calls.

Recording transcript

Full stack running locally in simulated/MOCK mode.

MarketPulse displays simulated live quotes and Gateway REST candles. A BUY is submitted through the order ticket, then the authoritative execution appears in Session Activity. A SELL closes the same position through the normal flow.

Core calculates Day P&L as -1.94 USD for 2026-10-04 in America/New_York, including commissions. The browser value is checked against Core.

The News tab shows synthetic news and synthetic-news.v1 interpretations. Session Activity retains the real simulated execution notifications.

Four services. Clear authority.

Quotes and financial truth follow separate paths

The browser calls Trading Core REST for domain truth and Gateway REST/WebSocket for bars and quotes. Core alone owns PostgreSQL. Core, Gateway and the isolated AI worker exchange events through Kafka. Redis holds disposable caches.

Trading Core Java / Spring

Order validation and lifecycle, execution accounting, exact decimal P&L, persistence, reconciliation and transactional inbox/outbox delivery.

Realtime Gateway Go

Market-data normalization, authoritative bars, bounded quote fanout and order-update hints that trigger Core refetches.

Web Terminal Next.js / React

Per-symbol quote subscriptions, one imperative chart, explicit uncertainty and notifications grounded in Core state.

AI Insights Python

Validated asynchronous enrichment with durable worker state, bounded resources and deterministic public fixtures. No trading capability.

Engineering decisions

Authority before optimism: HTTP submission success is not a fill. UNKNOWN stays uncertain; ambiguous attempts preserve their idempotency key for deliberate retry.
Financial precision: Core calculates New York Day P&L from execution cash flow, commissions, fresh marks and persisted opening valuations. Missing evidence stays unavailable.
Delivery with recovery: Stable event identities, database transactions and Kafka transactions make replay safe within explicit service boundaries.
Security boundaries: Kafka mTLS and service ACLs, nonce CSP, exact browser origins, bounded admission and isolated containers complement dependency and image verification.
Evidence over claims: Unit, contract, real-infrastructure integration, browser and failure tests exercise behavior. Performance comparisons separate security overhead from optimization benefit.

Workspace detail

MarketPulse simulated terminal with a watchlist, candlestick chart, order ticket, calculated Day P&L and synthetic news.

Actual simulated application capture. The hosted page is a static showcase, not an interactive trading service.

A trading terminal.A system built to explain its state.