Then at work I became C programmer, and, after a couple of years of ineffective C programming I realized that it benefits a lot to include perl chunks of code to speed up my programming, so I used perl as external library.
As time passed by, I used Perl more and C less, and then I switched to pure Perl, and I consider that as a very good boost for my efforts.
Still, I use my C knowledge regularry, but only to find a way how to make perl more capable for my tasks :)

As for my duties at work - I help to transform text files for language translation process, and many related tasks, which is quite interesting area for Perl programming.