Night life is awesome. Clubs and bars are crowded from Monday to Sunday, 10pm to 5am. That's what you get with a high population density. A bit expensive though.

Shenzhen is the world capital of electronics manufacturing, so there are lots of hardware gadgets that haven't yet made their way to the western world. I wouldn't say there are lots of hacker types around, but I know there are some e-commerce/SEO/etc. meet ups (see http://www.shenzhenstuff.com/groups).