Backend refers to the data access layer of a piece of software, its hardware, or its physical infrastructure. Typically, the backend handles business logic and data storage, while the front-end provides a user-friendly interface — in other words, the backend is what goes on "under the hood". In Stack Overflow’s 2018 survey, about 57.9 percent of developers identified as backend developers, 37.8 percent as front-end developers, and 48.2 percent as full-stack developers. Globally, backend developer hourly rates range from $61-80. See also: front-end developer hourly rates and full-stack developer hourly rates for a comparison.