The lack of consistency in development environments can lead to disparities between development and production, compromising quality and causing issues with QA teams. Ensuring consistent environments improves code quality, reduces finger-pointing, and boosts team morale. Vagrant has proven effective in building consistent and repeatable local environments by bootstrapping virtual machines within laptops/desktops and leveraging provisioners such as Chef or Puppet for setup and configuration. The combination of Vagrant and Chef ensures repeatability and consistency between local environments, making them disposable and allowing QA engineers to trust functional parity between environments. Task runners like Grunt and Guard can be used to automate unit tests and livereload, while continuous integration servers can call the same unit and browser tests before pushing builds to production.