[aldarn]

Do you specifically hire D3 developers? This sounds like a pretty difficult "coding challenge" for a non-D3 guy, let alone someone who may not even primarily use javascript. Having used D3 sparingly before i've found it something that requires a fair amount of upfront domain knowledge to get much done beyond something extremely simple (unless of course you copy an existing example, which is what I always did). This seems unreasonably difficult for someone with no prior knowledge to accomplish in a 48 hour window whilst working etc -- you may find you are inadvertently optimizing your interview process for the unemployed with this kind of time limit / coding investment.

[mpetrovich]

No, we're not specifically looking for experienced D3 devs. That particular challenge can be completed with the simplest D3 viz if desired (of which there are hundreds of examples online) and doesn't even require prior D3 experience (I didn't have any when I applied). We do look for a solid working knowledge of JS, however, and an ability to learn new tools quickly.

The 48 hour time limit is a relatively arbitrary timebox and isn't a hard limit; we value quality over speed.