Hadoop, written in Java, was designed in 2010 as a framework for distributed storage and processing of big data. Its primary function is to prevent hardware failures. Some notable users of this framework include Amazon E2C, Microsoft Azure, and Yahoo! On average, full-time Hadoop developers bring in an annual salary between $73,000 and $104,000. For those who freelance, Hadopp developers' hourly rate is around $81-100/hr on average. Also see Java developer hourly rates.