The modern application developer has undoubtedly dealt with the problem of process execution locality. More precisely, when responding to HTTP requests, developers must carefully balance what work is to be done in the process handling the request and the work that can be done in a process outside of the HTTP request. The Worker Pattern exists to help strike such a balance.

In this article, we will define the pattern and look at several applications of the pattern. However, before we dive in, a quick note on how to successfully grok this material. The fundamental idea of the Worker Pattern is and should always be simple. Much like mathematical techniques, the definition is quite simple and the application is not alway clear. However, with sufficient exposure to examples and with enough practice, the pattern becomes a reflex for the application developer.