"A product should not be ready to release to be ready to test."

In conventional software development, testing is typically conducted towards the end of the life cycle, right before deployment. In this case, the QA Engineers and testers must wait for the product to be prepared for testing before it is released. If there is a delay in any stages before testing during the Software Development Lifecycle (SDLC), it impacts the testing schedule as the deadline becomes tighter. Testing just before release often slows the process down, as rushing through it can lead to important bugs being overlooked. As they say,

"Hurry makes a bad curry."

The concept of starting testing at the beginning of SDLC was first introduced in the 1950s, and is now known as the Shift-Left testing approach. In this blog post, we will explore various aspects of Shift Left testing, including its advantages, execution, and difficulties.


Shifting the verification and validation phase earlier in the software development process is the main goal of Shift-Left testing (SLT), resulting in better detection of errors and bugs and enhancing testing and software quality. This method transforms the software development scenario by focusing on continual testing and integration at every stage.
Every participant in the project has a responsibility to carry out SLT, as it is a joint effort involving testers, developers, QA teams, and project managers. Integrating testing during the requirements and design stages allows development teams to identify and resolve issues sooner, leading to a substantial improvement in the efficiency and effectiveness of the development process.


Early testing is considered a fundamental principle among the seven principles of software testing, encompassing the idea of moving to the left. Let's explore the significance and advantages of SLT in the list provided below:

1. Early issue detection

Both major and minor bugs and issues can be detected and addressed sooner in the shift-left testing approach.

2. Cost reduction

The longer it takes to find the bug, the more expensive it is to fix. Utilizing a shift-left strategy can lower costs related to fixing bugs, resolving security vulnerabilities, and reworking features.

3. Quicker launch

Since testing happens alongside development, the testing tasks are decreased towards the end of the development phase, allowing the project to be deployed and released earlier than scheduled.

4. Closer collaboration with project members

The shift-left approach brings the development team, QA team, project leads and stakeholders together so that a collaborative sharing and understanding of project can be fostered.

5. Improved product quality

All members involved in the project planning stage understand the product being developed, leading to the refinement of the final result at every phase of the SDLC by developers, testers, and management teams.

6. Reduced risks

Identifying and managing risks at an early stage can prevent future issues from impacting the project. These dangers could involve security, adherence, efficiency, and capacity.

7. Continuous integration and continuous delivery

Shift-left testing integrates seamlessly with CI/CD practices, allowing for early and frequent automated testing to facilitate quicker and more dependable releases.

8. Better resource utilization

Proactively identifying and resolving issues prevents bottlenecks during later stages of development, making better use of available resources.

Talking about the suitability of adoption, it is possible to have misconceptions about how much emphasis to place on shifting left. Implementing shift-left in the project planning and requirement analysis phase, and maintaining it throughout the project lifecycle helps accelerate product delivery and reduces the possibility of last-minute failures. Various forms of testing in SLT need to be introduced at various stages. Unit tests should happen during coding, integration tests during building, and static analysis during code check-ins. Before starting to code, it is important to finish reviewing the requirements and design.

Implementing with Agile

In Agile, incorporating testing early in the software development lifecycle involves breaking down projects into smaller testable parts and conducting tests simultaneously with development. Testing begins during the requirements analysis stage. A developer is focused on transforming project requirements into code, while a QA is focused on finding ways to break the code and identify potential project malfunctions. During the planning phase, a developer predicts the cost, duration, and potential risks of the project, while a tester creates a test plan document and evaluates the project's associated risks. Similarly, during the implementation phase, the development team writes real code according to established coding practices while the QA team carries out functional and non-functional tests, all the while communicating with the development and business teams. Once the QA team gives the green light and confirms the product is ready for the market, the development team is approved to release it.

This reinforces the idea of ongoing testing and ongoing delivery. Incorporating automation scripts rather than manual tests helps verify that recent code updates do not impact previously corrected issues, and also facilitates the simulation of a wider variety of data sets as the project progresses. Leveraging automation tools enables faster and more dependable releases by facilitating swift regression testing during the final stages of the development process.


Besides the pros, there are some challenges to implementing shift-left approach as outlined below:

1. Shift planning

Effective collaboration between development and QA teams, along with adequate resource allocation, plays a vital role in various stages of the SDLC during shift-left testing. Inadequate planning of shifts can result in conflicts in scheduling, limitations in resources, and possible bottlenecks. To address this issue, providing team members with training in both development and testing skills can improve resource flexibility and readiness.

2. Team silos

Communication silos between the development and QA teams have been acknowledged but not openly discussed, stemming from a lack of interaction and communication within these teams. Testers and QA teams are typically brought in towards the end of software development in the traditional QA process, resulting in miscommunication and inadequate project comprehension. Therefore, having both the development team and quality assurance team involved from the beginning of a project can assist in bridging this divide.

3. Skill Gaps

As the shift-left testing approach requires team members to acquire both development and testing knowledge, it might be quite challenging for the dev team to implement testing strategies in their code and to code for QA teams. Rather than cross-team expertise, members must be able to understand the foundational principles of programming and testing.


In summary, shift-left testing combines integrating testing at all development stages, promoting a quality-focused culture, and using automation and continuous feedback loops for an efficient, high-quality development process. The incremental approach of identifying and fixing development bugs is more effective than waiting until the end for a big-bang approach.

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