San Francisco, CA
Academia.edu is a platform for sharing research. Fundamentally we are trying to massively speed up the rate at which research whizzes around the world. For people who have just published a paper, we want that paper instantly to get into the hands of people. For people who are following research, we want our News Feed to deliver them the latest papers in their fields in real time. 
Right now we have over 550,000 academics signed up, with about 2,000 joining each day. Our monthly uniques are over 2 million. We have about 700,000 papers, with about 80,000 new papers being added per month. Amongst other technologies, we work with Rails, Redis, MongoDB, Beanstalkd, Varnish, Solr, PostgreSQL, Node.js and Memcached.
We're a small team of 7 people in San Francisco, backed by venture capital (Spark Ventures) and angel investors (Mark Shuttleworth, founder of Ubuntu, and Rupert Pennant-Rea, Chairman of the Economist, amongst others). We have a very engineering-focused culture. You can read more about our culture here <a href="http://academia.edu/hiring/culture" >http://academia.edu/hiring/culture</a> and here <a href="http://academia.edu/hiring" >http://academia.edu/hiring</a>.
We have a very collaborative culture, where everyone discusses everything going on with the company: engineering, product, revenue, user growth, recruiting. We think that building a successful startup is hard enough that we need to leverage everyone's brain power.
We're very happy to handle the H1B application process for foreign applicants. For anyone interested to learn more, feel free to email me directly at richard [at] academia.edu