The Waterfall methodology is a traditional project management practice based on a sequential design process. As the name explains, the phases of a project flow from one completed task to the next and tend to be a very linear and rigid process.

The "Waterfall mindset" refers to a traditional, linear and sequential approach to project management. In this mindset, a project is viewed as a series of distinct phases—Requirements, Design, Implementation, Verification, and Maintenance—where each phase must be 100% complete before the next one begins. It follows the philosophy of "measure twice, cut once," emphasizing heavy upfront planning and detailed documentation. In 2026, while many tech industries favor "Agile" (iterative) mindsets, the Waterfall mindset is still highly valued in construction, manufacturing, and regulated industries where requirements are fixed and changes are extremely costly once execution begins. Critics of the mindset argue that it lacks the flexibility to adapt to feedback, as testing only occurs at the very end of the development cycle.