I'm not sure if you have international positions, the zip code search means I can't even be sure that just entering London would work (I get 404's when I try with values that I think should work if it were international).
Thanks for the feedback. Expanding international is definitely in the road map. There are a few companies outside the US that are posted, but unfortunately the location search wont find them.
Hope to have a whole bunch of new features out in the next week or two that will make the site even more useful!