"Don't just watch the crash. Rewind it."
A high-frequency trading visualization tool that records and replays cryptocurrency order books in real-time. Built for 60fps performance on mobile using a custom Zero-Garbage-Collection architecture.
This project was built to solve a specific systems engineering challenge: How to render 10Hz high-frequency market data on a mobile device without battery drain or UI lag.
- Challenge: Standard
ArrayListandRecyclerViewcaused micro-stutters due to frequent Garbage Collection (GC) events when processing 10 updates/second. - Solution: Implemented a fixed-size Ring Buffer and object pooling. The app runs with zero allocations during the render loop, ensuring a locked 60fps.
- Challenge: JSON payloads from Binance were too large (1.5KB/update) and CPU-intensive to parse on mobile.
- Solution: Wrote a custom Binary WebSocket Protocol. The backend compresses updates into a 640-byte binary blob (60% reduction), which the mobile app parses instantly using
ByteBuffer.
- Challenge: Handling thousands of concurrent WebSocket connections with traditional thread pools is resource-heavy.
- Solution: Leveraged Java 21 Virtual Threads (Project Loom) to handle high-throughput concurrency with minimal memory footprint.
- Challenge: Android's declarative UI (Compose) struggled to redraw complex order book depth charts at 60fps.
- Solution: Bypassed the standard UI toolkit to draw directly to the GPU using the Canvas API, calculating heatmaps and depth curves in real-time.
- Mobile: Kotlin 2.0, Jetpack Compose, OkHttp (WebSockets), Android Canvas API.
- Backend: Java 21, Spring Boot 3.3, Virtual Threads.
- Data Structure: Circular Ring Buffer (O(1) access).
- Protocol: Custom Binary Stream (ByteBuffer).
- Market DVR™: Records the last 5 minutes of market data in RAM. Users can "scrub" backward in time to analyze flash crashes.
- Real-Time Heatmap: Visualizes liquidity "walls" using color intensity.
- Order Book Imbalance: Calculates buy/sell pressure in real-time.
| Feature | 🔬 LiquidityLens | 🔶 Binance / Exchanges | ☁️ TradingView | 🗺️ Bookmap |
|---|---|---|---|---|
| Platform | Mobile First | Mobile & Desktop | Web & Desktop | Desktop Only |
| Order Book Visibility | Full Depth (Visual) | Basic List (Numbers) | None (on mobile) | Full Depth (Visual) |
| Market Replay (DVR) | ✅ Yes (5 min) | ❌ No | ❌ No (Bar Replay only) | ✅ Yes (Paid) |
| Performance | 60 FPS Native | Standard UI | Web-based | High Performance |
| Price | Free / Open Source | Free | Free / $15+ mo | $49 - $99 / mo |
cd backend
./mvnw spring-boot:run- Open
liquidity-lens-appin Android Studio. - Sync Gradle.
- Run on Emulator or Physical Device.
MIT License. Open Source.