Yahoo bought Tumblr for $1 billion this week. The company has come a long way in the past few years. Back in 2008, it was just a small startup when Jacob Bijani, an early Tumblr user, sent founder David Carp an email asking about a job listing. He wrote: "I was wondering if you are still looking to fill the position for creative developers." The job was full, but Carp, who had started following Bijani on Tumblr after he made some custom templates for the platform blogs, offered Bijani a job.