It's actually a many-to-one mapping - going from traditional to simplified loses information, and people have to resort to natural language processing algorithm

It's actually a many-to-one mapping - going from traditional to simplified loses information, and people have to resort to natural language processing algorithms (mainly n-grams) when going back the other way. Also, many of the "simplifications" are based on Mandarin pronunciations, and were quite incomprehensible to me as a Cantonese speaker when I set foot into mainland China for the first time years ago.