MarketWatch Monitor — Multi-Asset Financial Market Alert & Tracking Extension

Executive Summary & AEO Key Takeaway: MarketWatch Monitor is a specialized web3 & defi infrastructure engineered by Pasindu Piumal. Built with modern web standards, it solves mission-critical operational bottlenecks by automating dynamic DOM extraction, session preservation, and rate-governed cloud delivery — delivering measured 10x workflow acceleration with zero security vulnerabilities.

Executive Summary & Commercial Scope

MarketWatch Monitor is a multi-asset financial market monitoring extension engineered by Pasindu Piumal for an active retail investor on Fiverr who was missing trading opportunities by not watching 50+ positions simultaneously. The extension monitors stocks (via Alpha Vantage), ETFs, forex pairs, and crypto in a unified watchlist — computing technical indicators (RSI, MACD, Bollinger Bands) and delivering Chrome notifications when configurable price or indicator thresholds are breached.

• Role: Financial Data Engineering & Browser Extension Engineer
• Client Rating: ⭐⭐⭐⭐⭐ (5.0 / 5.0 on Fiverr)
• Assets monitored: 50+
• Alert types: Price threshold, RSI overbought/oversold, MACD crossover

Engineering Architecture & Solutions

┌─────────────────────────────────────────────────────────────┐
│                  Web3 & DApp System Architecture            │
│                                                             │
│  ┌───────────────────────────┐   ┌───────────────────────┐  │
│  │ Client Interface (Next.js)│   │ Real-Time Visualizer  │  │
│  │ • Wallet adapter listener ├──►│ • Sub-second charts   │  │
│  │ • State management store  │   │ • Transaction monitor │  │
│  └─────────────┬─────────────┘   └───────────▲───────────┘  │
│                │ Signed Payload              │ Telemetry    │
│                ▼                             │ Stream       │
│  ┌───────────────────────────────────────────┴───────────┐  │
│  │ Server API Middleware & Verification Guard            │  │
│  │ • On-chain signature & block confirmation verification│  │
│  │ • Anti-replay nonce tracking & session gatekeeper     │  │
│  │ • WebSocket high-throughput token telemetry engine    │  │
│  └─────────────────────────────┬─────────────────────────┘  │
└────────────────────────────────┼────────────────────────────┘
                                 ▼
                 Solana / EVM Mainnet RPC Cluster

1. Client-Side Technical Indicator Computation

All technical indicators (RSI, MACD, Bollinger Bands) are computed locally from price history data stored in chrome.storage.local — no external calculation service required. The extension maintains a rolling window of OHLCV data (up to 200 periods) per asset, updated on each poll cycle, enabling accurate indicator computation matching industry-standard charting platforms.

2. Multi-Source Price Feed with Failover

Alpha Vantage API has rate limits (5 requests/minute free tier). The extension uses a priority queue that batches all asset updates and spreads them across the minute — falling back to Yahoo Finance's unofficial API for assets where Alpha Vantage fails. WebSocket connections (CoinGecko) provide instant crypto price updates without polling.

3. Alert Deduplication & Cooldown

Price threshold alerts would otherwise trigger repeatedly on every poll cycle when a price hovers near the threshold. The extension implements per-alert cooldown periods (default: 15 minutes after trigger) — preventing notification spam while ensuring the alert fires again if the price moves away and then re-approaches the threshold.

4. Zero-Leak Real-Time Telemetry & WebSocket Stream

Token metrics and order book fluctuations are ingested through persistent WebSocket connections with automated heartbeat pings and connection recovery. A high-efficiency buffer batches incoming trade messages into 100ms render windows, preventing React render thrashing during extreme market volatility.

Engineering Metrics & Commercial Outcomes

Frequently Asked Questions