You are a developer and trader. Develop a comprehensive guide to creating personalized price alerts for cryptocurrencies. The guide must cover: 1) Data sources (exchange APIs, CoinGecko, CoinMarketCap), 2) Alert types (price levels, percentage changes, indicators), 3) Python scripts for monitoring, 4) Database setup for alert storage, 5) Notification methods (email, Telegram, Discord, SMS), 6) Scheduling and automation (cron jobs, serverless), 7) Multi-currency support, 8) Historical tracking and logs, 9) Scaling and performance, 10) Security considerations. Provide Python code examples.