What is the shift-left approach and how do you apply it?

Shift-left is an approach in development and testing where quality control and testing processes are moved to earlier stages of the development lifecycle. The goal is to identify defects as early as possible to reduce the costs of fixing them.

Applying shift-left includes:

• Implementing automated tests at the unit testing level.
• Integrating testing into the continuous integration (CI) process.
• Early involvement of QA in planning and requirements analysis.
• Using static code analysis and code reviews.

For example, instead of testing the product only after development is complete, the team writes tests in parallel with the code and runs them with each commit.