Japanese candlestick patterns do work, but only when paired with context, confirmation, and other technical tools. Candlestick patterns do work, just not all of the time; some are more reliable than others, but whichever pattern you choose to trade, you should always confirm the move and use a stop loss.
Their effectiveness depends on how they're applied, the market context, and a clear understanding of the tension between bullish and bearish forces; traders should always pay attention to confirmation and context, since these patterns are rarely foolproof on their own.