How-to guides

Shift-left security in SDLC: what you need to know

Get to grips with the concept of shift-left security in SDLC. Learn the best practices with this guide to ensure you can code with confidence.

Roy Horev | October 25, 2023

In today’s fast-paced world of software development, security can no longer be an afterthought. Traditional approaches often relegate security measures to the final stages of the Software Development Lifecycle (SDLC), leading to delayed releases and increased risks of vulnerabilities. Enter “Shift-Left Security”—a paradigm shift that aims to integrate security measures right from the get-go, thereby enhancing the overall quality and safety of the software.

KEY STAT: More than 99% of technologists say applications in production contain at least four vulnerabilities. (Contrast Security The State of DevOps Report)

This blog post delves into the concept of shift-left security, its significance in modern development practices, and the tools that facilitate this approach. We’ll also explore the challenges that organizations face when implementing shift-left security and offer industry-recommended best practices to overcome them. Whether you’re a developer, a security professional, or a business leader, this article will equip you with the knowledge and insights to make your SDLC more secure and efficient.

What is shift-left security? 

Simply put, the term “shift-left security” refers to moving security measures to earlier stages of the software development lifecycle (SDLC) as opposed to leaving it to the end or later stages. Organizations and teams often conduct security tests at the end of the development lifecycle. These tests, such as SAST and DAST, help to determine whether the application is ready to move on to production or if it should be sent back to development to fix any issues. But conducting tests at the end of the SDLC results in longer release cycles, delays in development, and the risk of releasing software with security vulnerabilities and threats.

The core idea behind the shift-left approach is to design applications with security best practices built in, detecting threats and vulnerabilities as early as the development process and addressing them then and there alone. This minimizes the number of errors passing through the various development stages, which means less work for QA, shorter release cycles, and reduced mitigation costs for the business.

The implications of keeping security right in the SDLC 

With the growing adoption of open-source software, third-party libraries, and cloud infrastructure, the security of your application is no longer tied to code alone. Security has, in fact, become heavily reliant on these external dependencies.

Open-source dependencies may contain critical vulnerabilities, which can easily pass through your build process if security measures are checked only in the final stages of the SDLC. Similarly, open-source communities create and share container images (e.g., Docker images and Kubernetes configurations), which could have vulnerabilities in them that then become part of your operational environment. This, in turn, could affect the security of your application.

Of course, if security testing is left to the final stages, when the application is ready for deployment, this could lead to lengthy delays in deployment or missed vulnerabilities in the production environment.

The significance of shift-left security

The introduction of DevOps and agile methodologies have led to radical changes in software development and delivery, accelerating the cycle of writing code and delivering better customer value based on market feedback. Legacy security practices and tools, on the other hand—which were designed for the slower-paced, pre-cloud era—place security teams under enormous pressure when it comes to delivering high-quality applications.

But organizations are slowly beginning to understand that security requires the same type of culture shift that application development has experienced since the early 2000s. To this end, the shift-left approach is helping security teams keep up with agile development methodologies while managing new security threats introduced by cloud.

Key benefits of adopting the shift-left security approach include:

  • Vulnerabilities are discovered at early stages rather than late in the software development lifecycle.
  • Security and development teams are alerted as potential vulnerabilities are detected, allowing for fast resolution during the development stage.
  • Fosters cooperation between security and development teams.
  • Allows developers to learn from mistakes and improve their security skills, leading to better code hygiene.Minimizes remediation costs by addressing vulnerabilities as soon as possible as opposed to later on, at deployment or following penetration testing.

Challenges in shift-left security

While every security team can benefit from adopting a shift-left approach, the methodology does present challenges for development teams. As a result, organizations and teams are often unable to implement the shift-left approach successfully.

KEY STAT: Half of security professionals report that developers fail to identify 75% of vulnerabilities. (GitLab Global DevSecOps survey.

Major obstacles to implementing shift-left security include:

  • Reluctance to adopt the approach: Fear and resentment among teams around the idea of shifting left is not uncommon. There could be multiple reasons behind this, such as overload, pressure to meet deadlines, and fast release dates. 
  • Team maturity: Teams with a low or medium level of maturity tend to struggle more when introducing security measures into their SDLC.
  • Lack of resources: Security teams are often understaffed, leading to more pressure on existing staff and fewer resources to successfully shift security left.
  • Lack of awareness: There are many developers across the industry who are unaware of common security risks and how to prevent them.
  • Poor collaboration: Creating an effective and secure SDLC requires all teams to work together closely, but until recently, there was often little to no collaboration between development, DevOps, and security teams.



Shift-left security tools

Next, let’s discuss some of the security tools that help in implementing shift-left security throughout the SDLC. Different tools serve different purposes and in different stages. In most cases, a combination of these tools is used to achieve a secure SDLC.


Software composition analysis (SCA) is a software analysis and security methodology. SCA tools are operated on open-source software components in order to track and analyze them. They identify such things as related modules, supporting libraries, software licenses, and the dependencies of the software components. SCA tools provide insights on potential threats, license limitations, security vulnerabilities, and data breaches, for example. Advanced SCA tools can automate the entire process of identifying components as well as detecting and remediating vulnerabilities, thus minimizing the overall risk.


Static application security testing (SAST) is a white-box testing methodology that examines source code to discover security vulnerabilities in the application. Because SAST analysis operates in an early phase of the SDLC, it doesn’t require working code or running applications. Rather, it is conducted in the early stages to ensure developers can resolve these flaws before releasing the final software solution into production. Integrating SAST in the earlier development stages and in the CI/CD pipeline makes it easier for developers to perform code scans and provide remedial solutions.


Dynamic application security testing (DAST) tools examine application source code in runtime to uncover security weaknesses. As a black-box testing methodology, it doesn’t require access to the source code to perform security scans. It is considered a shift-left approach because it scans the application during runtime or after its deployment to production. DAST analysis relies on fault-injection methods like SQL injections, detecting common issues like cross-site scripting (XSS). It also highlights problems such as server configuration issues, authentication-related issues, and insecure database issues.


Interactive application security testing (IAST) is a gray-box testing methodology that combines SAST and DAST approaches. It is usually operated in test environments as a proxy. IAST works from inside the application, allowing it to test on a wide range of things such as data flow, configuration files, libraries, and almost everything in the application. It uses some predefined test cases and additional test cases based on the results.

Best practices for shift-left security

Despite the popularity of the shift-left approach, organizations choosing to implement it are faced with a number of challenges. The struggles of early adopters of shift-left security, recommendations of security experts, and observations from across the industry have led to certain best practices that are now followed industry-wide when implementing the methodology.

Taking time to shift left

It would be rather impractical and unreasonable to expect developers to be able to take on the added responsibility of security while still maintaining the same pace of development. While shifting security left can certainly promote efficiency, fewer delays, and faster time to market, developers should be allocated sufficient time for these security tasks, like code reviews. Doing so will facilitate the process for both developers and the organization as a whole.

Defining security policies

Implementing security policies is a key and a good first step toward adopting a shift-left approach. Policies should be set up so that they consistently and automatically set boundaries and other security restrictions, such as access control, before the start of any project. This will ensure a more efficient and secure development process.

Enabling and encouraging security automation

Developers should be encouraged to embrace security automation tools, which use software to automatically detect, alert, investigate, and in some cases even fix external security threats to systems. Automation also contributes to a faster development lifecycle, in turn accelerating time to market.

Increasing visibility into the culture

One of the primary goals of the shift-left approach is to ensure that the application code is secure during every stage of development and following release. Achieving this requires that development and security teams have visibility into application security at all times. This will allow them to remediate security issues in any upcoming software releases.

Security awareness, assessment, and training for development teams

Another key component to the successful implementation of the shift-left approach is seeing that the developers responsible for creating most of your application code know how to write secure code and to create the most secure applications possible to begin with. This requires assessing your development team’s security skills and providing them with training, awareness, and guidance in application security.

Understanding the limitations

Some activities in the SDLC, such as UX manual testing, can only happen closer to or after production release. These tasks cannot be shifted left from the security perspective and are performed better and more efficiently after the build cycle. Thus, you should focus on activities that can indeed be shifted left and that would benefit from shift-left security.


The shift-left approach plays an important role in ensuring a more secure and efficient SDLC, but it must be implemented carefully and responsibly in order for it to be successful. By providing your development teams with the knowledge, guidance, and tools needed to integrate security into their existing development workflows, you’ll be able to significantly decrease security risks in production and accelerate time to market. Using the tools and best practices discussed in this article can help kickstart your journey to shift-left security.

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