This looks like a bold move, but taking into account that Delicious had a complex system to support a really simple set of features; it looks like the rewrite is worth just to get rid of all the code debt this Web App had.
Does anyone else have any other examples of other companies who have dared to do this?
The other only example I can think of the top of my mind that has dared to do this is Foursquare (Ditching PHP & MySQL for Scala & MongoDB), and it looks like they are doing ok.
