From Joomla! Documentation
Only short after Joomla! came into the world, the Quality & Testing Working Group was created to test and evaluate major and minor releases for security, stability and performance issues. The team should organise, process and test reports and suggestions provided by the community in order to further improve the code base between major and minor releases.
The release of Joomla! 1.5 Beta2 marked the transition from the Development Working Group leading the process to the Quality & Testing Working Group leading the development process. The focus thus had officially shifted from features to stability and security. Unfortunately, because of the long period of down time between the release of Joomla! 1.0.12 and the change of lead to the Quality & Testing team for the Joomla! 1.5 cycle, many of the Quality & Testing members had disappeared. The team was overburdened with the process, so finally in September 2007, the Quality & Testing Working Group was disbanded.
To fill the gap, the first Pizza, Bugs and Fun event was organised, with Joomlers gathering in New York, San Francisco, Washington DC, Vancouver and Brussels in the beginning of December 2007. In three days around 100 commits were processed and 88 artifacts closed.
During the PBF event, the idea for a new team was born. The team was called "The Bug Squad", and should help out organising the handling of the feedback process, keep the tracker up to date, perform testing, guide people in the forums and during PBF events, and provide patches to the Development Working Group, to which the Bug Squad would be a sub-team.
In May 2010, the Joomla! Bug Squad (JBS) had been organised into the different teams: a Tracker Team to monitors the forums and trackers, a Coding Team to create patches for confirmed issues, a Testing Team to test pending issues, an Automated Testing Team to create automated system and unit tests for tracker issues, and a Migration and Upgrade Team to support migration and upgrading from the prior version to the current version.
In the following years, the team structures changed a lot. The introduction of the Volunteers Portal made most of the working groups bubble to the main level. A System Testing Working Group and a Unit Testing Working Group were created and in January 2015 combined into the Automated Testing Working Group on the same organisational level as the Bug Squad. Specific Release teams were in charge to support migration and upgrades.
With the transition to the new structure, in January 2017, the Joomla! Bug Squad, as any other team in the Production Department, had to redefine its purpose, function and roles. This was an opportunity for JBS to reflect on its origins. While the purpose still was to reduce the number of bugs in Joomla, not only for the CMS, but for every Joomla project, helping and mentoring developers and contributors with bug squashing gained significant importance.