How we built Israel's most-downloaded stock trading app
IBI Investment House came to us with a problem: Israeli retail investors had no good way to trade US stocks from their phones. The existing platforms were clunky, slow, and designed for desktop. IBI wanted something that worked for both first-time investors and experienced traders.
We built IBI Smart from initial specification to App Store launch. The result: 500,000+ downloads, a 4.9-star rating on Google Play, and the highest user retention rate of any trading app in Israel.
The technical challenge
Building a stock trading app is not like building a typical consumer app. Every feature touches real money and is subject to financial regulation.
Real-time market data. Stock prices move every millisecond during trading hours. The app needs to display live prices for thousands of US-listed securities with sub-second latency. We built a WebSocket-based data pipeline that handles 50,000+ price updates per second during peak market hours.
Regulatory compliance. Israeli financial regulations (ISA) and US market regulations (SEC/FINRA) both apply. Every transaction, every screen, every notification has to be compliant. We worked with IBI's compliance team throughout development, not just at the end.
Security architecture. Users link real brokerage accounts. The app handles PII, financial data, and authentication tokens. We implemented certificate pinning, biometric authentication, encrypted local storage, and real-time fraud detection.



