Comprehensive MQL4/MQL5 development for MetaTrader 4 and MetaTrader 5 platforms. Use when writing, reviewing, debugging, or architecting: Expert Advisors (EAs), custom indicators, scripts, libraries (.mqh), graphical panels, or any MQL code. Also use for: order/position management, risk management, backtesting strategies, communication with external APIs (WebRequest, REST, JSON), inter-program communication, code protection/licensing, and MQL4-to-MQL5 migration. Covers the full MQL ecosystem including trading automation, technical analysis, UI panels, and server integration.