Shift Left Security refers to the practice of integrating security measures early in the software development lifecycle (SDLC) - ideally, as soon as the planning and design phases begin. The term "shift left" comes from the traditional SDLC model, where testing and security activities often happen toward the end (on the "right" side), but in Shift Left, these activities are "shifted" to the left, i.e., earlier in the process.

Example of Shift Left Security in Action:

Imagine a software development company working on a new web application. Traditionally, security checks might be done at the end of the development process - just before the app is deployed. If any vulnerabilities are discovered, they may require significant code changes, which could delay the release. In a Shift Left Security approach, however, the company implements security measures early. Developers use static analysis tools to detect issues as they write the code, and automated tests check for vulnerabilities each time new code is pushed to the codebase. Security experts are involved during the design phase, identifying potential risks in the architecture, and developers follow secure coding practices to prevent common vulnerabilities. As a result, vulnerabilities are caught and fixed early, allowing the application to be deployed faster, with greater confidence that it's secure.