TL;DR

Shift left is a software development approach that emphasizes moving testing, security, and quality assurance activities earlier in the development lifecycle. By identifying and addressing issues earlier, teams can reduce costs, improve quality, and deliver software more efficiently.


Concept

Shift left is a strategy in software development that aims to move testing, security, and quality assurance activities to the left side of the development timeline, meaning they are performed earlier in the process. This approach contrasts with traditional methods where these activities were often left until later stages, such as before deployment or release.

Key Principles of Shift Left:

  1. Early Issue Identification: By testing and assessing quality earlier, teams can identify and address issues as soon as they arise, reducing the cost and complexity of fixing them later in the development cycle.

  2. Continuous Testing: Shift left emphasizes the importance of testing throughout the development process, rather than relying on a single testing phase at the end.

  3. Shared Responsibility: Shift left promotes the idea that everyone on the team, not just dedicated testers, is responsible for quality and security. Developers play a key role in writing testable code and implementing security best practices.

  4. Automation: Shift left relies heavily on automation to streamline testing and quality assurance processes, enabling teams to run more tests more frequently.

Shift left is a powerful approach that helps teams deliver higher-quality software more efficiently by moving testing, security, and quality assurance activities earlier in the development lifecycle. By identifying and addressing issues as soon as they arise, teams can reduce costs, improve collaboration, and deliver software faster. Implementing shift left requires a combination of tools, processes, and a culture of shared responsibility for quality and security.