Shift-Left Testing
A testing strategy that moves testing activities earlier in the software development lifecycle, catching defects sooner when they are cheaper and easier to fix.
Traditionally, testing happened at the end of development, after features were fully built. Shift-left testing challenges this by involving QA from the requirements phase onward. Practices include: reviewing acceptance criteria and designs for testability, writing test cases before development begins, developers writing unit tests as they code (TDD), and running automated tests on every commit.
The economics are compelling: a bug found during requirements review might take minutes to fix, while the same bug found in production could require emergency patches, customer communication, and data remediation.
Why It Matters for QA Teams
The later a bug is found, the more expensive it is to fix. Shift-left testing catches defects when a conversation or quick code change is all it takes, instead of a costly production hotfix.
Example
During a design review, a QA engineer notices that the proposed form has 12 required fields on a single page with no validation feedback until submission. Before any code is written, the team redesigns the form into three steps with inline validation, preventing dozens of usability bugs that would have been filed later.