A programmable autonomous business is a kind of online software agent whose function is not to collect or synthesize information for people, but rather to gather and generate customers and income for entrepreneurs. Functionally and compositionally autonomous businesses are indistinguishable from conventional ones. However, an autonomous business is built entirely in software and capable of operating profitably without any employees or managers guiding it. This paper analyses an instance of a successful autonomous business — uncovering the processes driving the production of its symbols. A general architecture for symbol engines is induced from these processes. The paper discusses how this architecture applies to other successful autonomous businesses, and concludes with a set of design requirements for symbol engines in autonomous businesses.