Who Wrote the Haggadah? https://mosaicmagazine.com/picks/uncategorized/2014/04/who-wrote-the-haggadah/

April 17, 2014 | Elon Gilad
About the author:

The book read today would be unrecognizable to the ancient Jews who first devised the home ritual of the seder.   

Read more on Haaretz: http://www.haaretz.com/jewish-world/passover/1.585589