Comment by RobertoG

In my opinion, the best fiction book about this subject is 'Permutation City' by Greg Egan.

Also, this one is pretty good:

https://sifter.org/~simon/AfterLife/index.html

And, in a very similar line to "Lena", this one by Vernor Vinge:

https://en.wikipedia.org/wiki/The_Cookie_Monster_(novella)