Below you can see and read about a short experiment with ESP8266 CBDB Board and pushbuttons play or how to use a First order Low Pass Filter combined with Interrupt Trigger on falling/rising edge technique to obtain a very clean response over a broad range of key pressing speeds.
Link http://www.esp8266-projects.com/2015/03/buttons-pushbuttons-and-debouncing-story.html
Available on Tindie: https://www.tindie.com/products/nEXT_EVO1/universal-ac-mains-dimmer-mpdmv41/