Dan Zhang currently works at Qutke in the field of internet finance, leading a startup business of quantitative investment. As a programmer, he has worked in the area of program development for over ten years. Dan has developed mobile games as well as programming tools, and has worked on large Web application systems, internal CRM of companies, system integration of SOA, and big data tools based on Hadoop. Outsourcing, ecommerce, group purchase, payment, SNS and mobile SNS are all within his working range. He is familiar with four programming languages: R, Java, PHP, and JavaScript, and is knowledgeable of mass data storage, data analysis, and machine learning. His blog (http://blog.fens.me/) has a lot of R language original article.