[paraschopra]

When I was in initial years of programming my first hardest problem was implementing backpropagation in VB 6.0 http://paraschopra.com/tutorials/nn/ (2003)

Then the next hardest problem I found was implementing Genetic Programming in Python (year 2005) http://paraschopra.com/sourcecode/GP/index.php

It was fun but extremely hard for me (at that age!).

After that in 2008, I think the trickiest part for me was to write initial visual editor for Visual Website Optimizer. It involved reverse proxy and inserting JavaScript code into that reverse proxied page, letting the user visually edit the page contents.

Fun days. These days I hardly get to code, though last year I gifted my wife a website (http://wowsig.com) which was super fun.