LinkedIn is a professional networking site with over 175 million members worldwide. In 2012, it generated $522 million in revenue, with 53% from hiring solutions, 28% from marketing solutions, and 19% from premium subscriptions. It has built several open source projects like Kafka for data pipelines and messaging. LinkedIn has a strong culture that emphasizes work, learning, innovation, and play. It recruits top interns and offers opportunities in many technical areas including application development, data science, and mobile.