Market Screener (data-heavy)

A fast, accessible market screener for 10k+ equities and ETFs, built with Angular and Nx.

Work in progress. The full README (problem, live demo, screenshots, decisions and quality numbers) is written once the features are in place.

Getting started

Requires Node 24 (see .nvmrc).

nvm use
npm ci
npm start            # http://localhost:4200

Commands

Command	What it does
npm start	Dev server for the screener app
npm run build	Production build
npm test	Unit tests (Vitest) for all projects
npm run lint	ESLint, including module boundary rules
npm run typecheck	ngc/tsc type checks, including templates
npm run e2e	Playwright journeys with axe checks
npm run format:check	Prettier check
npm run data:generate	Regenerate the market data snapshot (also runs before build/serve)
npm run lighthouse	Lighthouse CI against the production build (build first)
npm run perf:measure	Before/after performance measurements (build first)

Data

The app runs on a synthetic, deterministic dataset of 10,000 equities and ETFs. Company names and figures are generated and do not refer to real companies. See tools/market-data and ADR 0006.

Add ?rows=50000 to load a 50,000-row stress dataset, and ?naive=1 to compare with a naive implementation (every row in the DOM, filtering and sorting on the main thread). See docs/performance.md.

Documentation

• Architecture decision records
• Performance: targets, measurements and budgets
• Deployment