Waterfall testing

Waterfall testing happens after all development is complete, unlike Agile testing which runs continuously. The development team must finish requirements, design, and coding before any testing begins. 

In banking software, teams document all features, design the interface, and build the complete application before testing starts. Testers then work through the entire system, checking everything from logins to transactions in one final phase. 

Waterfall testing works well for systems that need extensive documentation and thorough validation. It's particularly effective for medical devices and financial systems where regulations are strict and changes are rare. 

Finding bugs months after the code was written makes fixes expensive and complex. Late-stage changes can force rebuilds of major system components. While Agile projects can adapt quickly, waterfall projects get locked into their initial requirements, making changes difficult and costly.