Ideas from func­tion­al pro­gram­ming have been incor­po­rat­ed in pret­ty much every larg­er ecosys­tem one can work with today. Whether it’s reacts con­cept of “UI as a func­tion of state” or pat­tern match­ing in C#, these ideas are tak­ing root more and more in todays envi­ron­ments. Like with any oth­er ideas it pays to under­stand where they come from, what they actu­al­ly mean and most impor­tant­ly: how you can lever­age them to com­mu­ni­cate your ideas effi­cient­ly, both to your com­put­er and to your col­leagues. Take a seat and dis­cov­er how every­thing “new and shiny” today is actu­al­ly built on con­cepts that have been honed for the past 400 years.