Yesterday I wrote an article about Pinterest co-founder Paul Sciarra stepping down. We did not know where he was headed until today. Now we know that he is going to be making his way to Andreessen Horowitz as an entrepreneur-in-residence. ?I hope that eventually leads me back to doing what I?ve done for the past three and a half years ? namely, building cool things with awesome people with unexpected results,? said Sciarra in a blog post. Andreessen Horowitz is an investor in Pinterest.