DevOps is a new movement that officially started in 2009 in Belgium, when a group of people met at the first DevOpsDays conference, organized by Patrick Debois, to talk about how to apply some agile concepts to infrastructure.

Agile methodologies transformed the way software is developed. In a traditional waterfall model illustrated in the following diagram, a Product team comes up with specifications, a Design team then creates and defines a certain user experience and user interface, the engineering team then starts implementing the requested product or feature and hands off the code to a QA team, which tests and makes sure that the code behaves correctly according to the design specifications. Once all the bugs are fixed, a Release team packages the final code that can be handed off to the Technical Operations Team, which deploys the code and monitors the service over time:

The increasing complexity of developing certain software and technologies showed some limitations with this traditional waterfall pipeline.

The agile transformation addressed some of these issues, allowing for more interaction between the designers, developers, and testers. This change increased the overall quality of the products as these teams now had the opportunity to iterate more on product development; but apart from this, you would still be in a very classical waterfall pipeline:

All the agility added by this new process didn't extend past the QA cycles, and it was time to modernize this aspect of the software development life cycle. This foundational change to the agile process, which allows for more collaboration between the designers, developers, and QA teams, is what DevOps was initially after, but very quickly the DevOps movement started rethinking how developers and operations teams could work together.