Image represents a media kit with boilerplate, logos and more

Definition and Guide

shift left developer's guide

"Shift Left" is a practice that involves moving critical development practices earlier in the software development lifecycle (SDLC).

Table of Contents

What is Shift Left? 

"Shift Left" is a practice that is all about integrating critical development practices, such as testing, security measures, and quality assurance (QA), earlier in the software development lifecycle (SDLC). This strategy aims to identify and rectify issues as early as possible in the development process, thereby mitigating risks, reducing costs, and improving the overall quality of the software product. 

This means that QA and testing to uncover issues are included in the development process from the beginning, rather than waiting until the code is finished before beginning testing.

The Shift Left approach is often associated with Agile and DevOps methodologies, emphasizing quick feedback loops, learning from mistakes, and adapting processes accordingly. 

Its adoption, facilitated by automated testing tools and CI/CD technologies, has been growing in the industry due to its potential for cost-efficiency, improved quality, and faster time to market, despite challenges like the need for a change in organizational culture and resource allocation.

Why is Shift Left important?

Shift Left is significant because it emphasizes early problem detection, quicker resolution, and a relentless focus on delivering high-quality, secure, and reliable software products. It saves costs and can speed up delivery by focusing on finding and fixing bugs as soon as possible in the development process. 

Shift Left can also aid in the improvement of communication and collaboration between developers and QA engineers, resulting in a better knowledge of software requirements and a more efficient development process. This can lead to increased developer satisfaction and a competitive advantage in the marketplace. 

How to Shift Left

Adopting Shift Left involves several principles and practices. Some common approaches include:

Static Analysis

Static code analysis is a technique to examine code without executing it. It involves analyzing the source code for potential issues, bugs, vulnerabilities, or code quality violations before the code is run or compiled. 

By analyzing the code using static code analyzers, developers can identify issues such as memory leaks, buffer overflows, and other potential vulnerabilities before the code is merged into the main branch. 

This early detection of bugs, vulnerabilities, and other coding discrepancies allows for a more streamlined and less error-prone development process, which in turn enhances the overall software quality and security. 

Integrating static code analysis tools into the CI/CD development workflow aids in catching issues early, reducing bugs, enhancing code consistency, and ensuring adherence to best practices and coding standards. 

SonarQube, SonarCloud, ESLint, Pylint are some of the commonly used Static Analysis tools. 


Code and software testing ensures quality by detecting issues, and guaranteeing that the final product meets functional, performance, security, and user expectations. 

Integrating various testing approaches throughout the software development lifecycle is crucial for delivering high-quality, performant, and functional software. Commonly adopted Testing approaches include:

  • Unit testing is a fundamental practice in which developers write small, focused tests to verify the functionality of individual units of code. Each unit test is designed to ascertain that a specific aspect of the code operates as intended under various conditions. By validating the correctness of individual units, developers can ensure that each building block of the software is robust and reliable, which is crucial for the overall functionality and stability of the application. Tools such as JUnit, NUnit, or Jest are often employed for unit testing.
  • Integration Testing - Once the individual units of code have been tested and verified, integration testing is carried out to ensure that these units work harmoniously together as intended. During this phase, different units of code are combined and tested as a group to identify any issues that may arise from their interaction. Integration testing helps uncover problems that may not be visible when the units are tested in isolation, thereby ensuring the seamless interoperability of different parts of the software. Tools such as Selenium, or Postman can aid in integration testing.
  • Acceptance Testing:  Acceptance testing is a critical phase where the software is tested to ascertain that it meets the specified business requirements and is ready for deployment.  This form of testing is typically performed by quality assurance teams or end-users to validate that the software behaves as expected under real-world conditions. By verifying that the software aligns with the business goals and user expectations, acceptance testing helps ensure that the software delivered is of high quality and is well-suited for its intended purpose. Cucumber, FitNesse, and Robot Framework are examples of some acceptance testing tools.

What are the benefits of Shifting Left? 

Shifting Left in the context of software development and testing can offer a variety of benefits, which are primarily aimed at enhancing efficiency, quality, and collaboration. Here’s a detailed examination of the benefits of a Shift Left strategy:

Early Defect Detection

Identifying defects early in the development process allows for quicker and more cost-effective resolution, which is crucial for maintaining project timelines and budgets.

Cost Efficiency

Resolving issues in the early stages of development is usually cheaper compared to fixing bugs found later in the cycle or post-deployment.

Improved Quality

Continuous testing from the onset of a project can significantly improve the quality of the final product by ensuring that issues are addressed as they arise.

Faster Time to Market

By reducing the number of defects and rework in the later stages of development, projects can be completed faster, leading to a quicker time to market.

Enhanced Collaboration

Shift Left encourages collaboration among developers, testers, and operations from the beginning, which fosters a culture of shared responsibility and better communication.

Customer Satisfaction

Delivering a high-quality product in a timely manner can significantly enhance customer satisfaction, which in turn can lead to better market reception and competitive advantage.

Continuous Improvement

The feedback loops and early testing ingrained in Shift Left foster a culture of continuous improvement, enabling teams to learn and adapt quickly.

Risk Mitigation

By identifying and addressing issues early, the risk associated with project failures, non-compliance, or security breaches can be significantly mitigated.

Support for Agile and DevOps

Shift Left aligns well with Agile and DevOps methodologies, promoting a culture of continuous delivery and integration which is pivotal for modern software development practices.

Competitive Advantage

In markets where delivery speed and product quality are key differentiators, the Shift Left approach can provide a significant competitive advantage.

Predictability and Planning

Early identification of issues and continuous feedback allow for better predictability in project timelines and resource allocation, aiding in more accurate planning and decision-making.

These benefits are essential for organizations looking to remain competitive and agile in the rapidly evolving landscape of software development.

What is Shift Left security? 

Just as Shift Left focuses on moving everything earlier in the Software Development Lifecycle (SDLC), Shifting Security Left embodies a software development approach that underscores the integration of security measures earlier. This notion propels security considerations from being mere end-stage evaluations to integral facets of the entire development journey.

While Shift Left security can be seamlessly incorporated within any software development paradigm, it fits exceptionally well with agile methodologies. 

The agile ethos, with its hallmark iterative development and perpetual testing, lays a fertile ground for weaving security activities throughout the developmental process.

Static Application Security Testing (SAST) is one of the key components of Shift Left security. SAST solutions analyze source code for security vulnerabilities, coding errors, and potential weaknesses without executing the application. 

By integrating SAST into the early stages of development, developers can identify security flaws and coding issues during coding itself. 

This proactive approach enables developers to fix vulnerabilities before they evolve into significant security risks and before the code reaches further stages in the development pipeline. 

SonarQube and SonarCloud provide robust static code analysis and SAST capabilities, identifying coding issues, vulnerabilities, and security weaknesses across various programming languages to enhance code quality and security.

Embracing the Shift Left security approach can significantly bolster the security posture of applications. 

Adhering to the insights provided, organizations are well-poised to diminish the likelihood of security infringements, thereby safeguarding their clientele's invaluable data.

Why does DevOps recommend Shift Left testing principles?

DevOps advocates for the adoption of Shift Left testing principles due to the alignment with the fundamental DevOps tenets of Continuous Integration and Continuous Delivery (CI/CD). CI/CD is the practice of automating the build, test, and deployment phases of software, fostering a culture of frequent releases coupled with enhanced quality.

The principle of Shift Left testing is to transpose testing activities earlier within the Software Development Lifecycle (SDLC). This proactive stance allows for the swift identification and rectification of defects before they escalate into more costly and time-sensitive issues to resolve. 

The effect is a notable enhancement in the software's quality and a streamlined release cycle.

On a broader view, shift left testing principles are a potent strategy for refining the quality, cost-efficiency, and velocity of software development. 

By advancing testing activities earlier in the SDLC, DevOps teams are poised to deliver superior-quality software to customers with greater frequency.

Shift Left testing principles act as a robust catalyst in ameliorating the software development framework. 

By heeding the guidelines outlined, DevOps teams can adeptly implement shift left testing principles, unlocking the myriad of benefits they harbor.

Sonar and Shift Left 

Sonar complements and fulfills the shift left approach by providing a comprehensive solution in their Clean as You Code methodology. 

Sonar provides a wide variety of automated code quality and security checks throughout the SDLC. This enables organizations to identify and fix issues early on before they become more expensive and time-consuming to fix. 

SonarLint, integrated into developers' IDEs, performs real-time code analysis as code is being written. It instantly flags issues, such as bugs, vulnerabilities, and code quality concerns, providing immediate feedback to developers as they code.

SonarQube and SonarCloud offer powerful static code analysis capabilities. They seamlessly integrate with CI/CD pipelines, continuously scanning code changes for bugs, security vulnerabilities, and code smells. This proactive analysis ensures early issue detection and prevention.

Sonar can be used by developers, QA engineers, and security engineers, which helps in breaking down silos and encouraging collaboration between different teams.

How Sonar fulfills the Shift Left approach

Sonar’s products (SonarLint, SonarQube, SonarCloud) can be utilized to leverage effective shift left practices to find quality and security issues in the code, infrastructure, and build process; allowing organizations to tackle issues at their root cause before they potentially impair the software. 

By leveraging Sonar’s suite of tools, developers can implement a comprehensive shift left approach, enabling continuous monitoring, early issue detection, and proactive improvements in code quality and security throughout the software development lifecycle.

The Shift Left Solution

Shift Left with Sonar


next level linting with SonarLint

Up your coding game and discover issues early. SonarLint takes linting to another level empowering you to find & fix issues in real time.

Install SonarLint -->

Clean Code for teams and enterprises

Empower development teams with a self-hosted code quality and security solution that deeply integrates into your enterprise environment; enabling you to deploy clean code consistently and reliably.

Download SonarQube -->

Clean Code in your cloud workflow

Enable your team to deliver clean code consistently and efficiently with a code review tool that easily integrates into the cloud DevOps platforms and extend your CI/CD workflow.

Try SonarCloud -->