DevOps is a culture and set of practices aimed at uniting software development and IT operations, the two groups that traditionally built software and ran it as separate, often conflicting functions. The intent is to let an organization deliver and operate software both reliably and quickly, by sharing responsibility across the boundary rather than handing finished code over a wall.
The term gathered momentum around a conference series. According to the DevOpsDays organization’s own history, “the first devopsdays was held in Ghent, Belgium in 2009,” organized by Patrick Debois, who is identified as the founder and lead of the events from 2009 to 2014. The conferences describe themselves as covering “software development, IT infrastructure operations, and the intersection between them,” which captures the concern at the heart of DevOps.
In practice, DevOps draws together a number of technical practices that had been developing in parallel: continuous integration and continuous delivery for moving changes safely into production, treating infrastructure as code so that servers and environments are provisioned automatically and reproducibly, and monitoring so that the behavior of running systems feeds back into development.
Rather than a single tool or fixed process, DevOps is better understood as a cultural shift supported by automation. The DevOpsDays events gave the loose collection of ideas a shared name and a recurring venue, and from 2009 onward the term spread rapidly through the industry as organizations reorganized to close the gap between writing software and operating it.