Crypto & Stock Trading App with Real-Time Portfolio

A fintech startup wanted to build a unified trading platform where users could trade crypto, stocks, and ETFs from a single mobile app. The core requirement was speed: real-time price feeds, instant order execution, and live portfolio tracking with zero lag. They also needed a clean, intuitive UI that could compete with established players like Robinhood and Coinbase.

The technical bar was high. The app had to handle massive concurrent users, process financial transactions securely, and meet regulatory compliance standards.

We designed and developed a full-featured crypto and stock trading app for iOS and Android, built for performance and scale.

Real-time portfolio tracking with live charts and P&L calculations

Crypto trading (Bitcoin, Ethereum, Solana, 200+ tokens)

Stock and ETF trading with market, limit, and stop-loss orders

Live price feeds with candlestick charts, technical indicators, and depth charts

Watchlists with custom alerts and price notifications

Secure wallet system with multi-currency support

KYC/AML verification flow for regulatory compliance

Two-factor authentication and biometric login

Transaction history with detailed trade logs and tax reporting

Subscription tiers with premium features (advanced charting, priority execution, research reports)

Push notifications for price alerts, order fills, and market news

Frontend: React Native (cross-platform iOS & Android)

Backend: Node.js with high-throughput RESTful and WebSocket APIs

Cloud Infrastructure: AWS (EC2, ECS, RDS, ElastiCache, CloudFront)

Database: PostgreSQL for transactional data, Redis for real-time caching

Real-Time Data: WebSocket connections for live price feeds and order book updates

Security: End-to-end encryption, OAuth 2.0, biometric authentication

Payments: Stripe, Plaid integration for bank linking and ACH transfers

Monitoring: Datadog for performance monitoring and alerting

I led the full development lifecycle: system architecture designed for high concurrency, mobile UI/UX implementation, backend API development, real-time data infrastructure, payment and wallet systems, security implementation, and App Store/Play Store deployment. I worked closely with the compliance team to ensure all trading features met financial regulatory requirements.

2,000,000+ users within the first year

$265 million in total transaction volume processed

Successfully launched on both App Store and Google Play

Sub-100ms order execution latency

99.99% uptime across trading infrastructure

Featured in fintech publications as a top emerging trading platform