SMPLNVST Paper Trading App
Software Design and Development · 2026
SMPLNVST is a paper trading app that helps people learn the basics of investing and simulate stock market portfolios using real-time market data.
The product focuses on presenting trading workflows and portfolio performance in a way that feels clear, understandable, and less intimidating than traditional trading platforms.
Throughout the experience, users are introduced to investing concepts and financial terminology in context, helping them build confidence as they develop long-term investing habits and explore different trading strategies.
I designed and built the entire software experience from the ground up to make virtual trading, portfolio tracking, and performance analysis feel approachable for beginners while still useful for more experienced investors testing strategies.
Every surface — the marketing landing page, the trading flows, modals, charts, and portfolio analytics — was designed and engineered as one cohesive system, anchored by a custom shared component library.
The codebase is structured as a TypeScript monorepo: a React + Tailwind web app and a planned React Native (Expo) mobile app share a common core package that owns the data hooks, API adapters, and investing calculations — cost-basis lot tracking, realized and unrealized gains, wash-sale detection, dividend and stock-split handling — so business logic stays consistent across platforms while each app still owns its native navigation, auth, and storage.
Live market data flows through a custom server-side adapter on Supabase Edge Functions (Postgres, row-level security, two-level caching) so the upstream API key stays off the client and data fetches amortize across users.
Tech Stack
- Frontend: React 19 · TypeScript · Tailwind 4 · Vite · React Native + Expo · Recharts · TanStack Query · dnd-kit
- Backend: Supabase · Postgres · Edge Functions (Deno) · Row-Level Security · pg_cron
- Market data: Massive API · two-level server-side cache
- Infrastructure: Cloudflare Pages (static + SPA, _redirects-driven routing) · auto-deploy on push to main
Portfolio summary
Stock ticker details
Sell shares
