Python, iPython, Pandas (especially the GA module), MRJob lately, S3, MixPanel, GA, Sublime Text 2, Omnifocus, Tableau, NLTK a bit, GIT, and less so every day but some R.
I'm a product optimization specialist which means I'm focused largely on split testing and understanding conversion rates of our website. I also dig through our data looking for insights that can inform our future testing direction.
It's a role that's odd in that it sits somewhat between marketing, product, and technology groups.