What is the Secure Software Development Lifecycle (SSDL)? Everything Explained! 


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Secure Software Development Lifecycle

Today, IT-driven companies face a lot of pressure to modernise their applications, automate workflows, migrate to the cloud, and enhance customer experience. However, achieving a smooth, successful and secure application development remains an immovable milestone for many. 

In fact, a recent survey suggests that only 36% of businesses can rate their security testing program at 9 on a scale of 10. And, 48% don’t entirely rely on their set secure development processes, often they end up including vulnerable codes in production. 

Fortunately, businesses can implement the secure software development lifecycle (SSDL) policy to mitigate these risks.  

Secure software development lifecycle or SSDL entails integrating real-time security testing tools alongside other practices with the actual development process. 

For example, your product engineers can write various security requirements together with functional requirements and perform a simultaneous architecture risk analysis during the design phase. Alternatively, look at it as a ready-made approach that can be implemented at any software development or maintenance stage for enhanced security, as well as compliance. 

How SDLC Can Be Connected? 

A secure SDLC is what many developers refer to as a “shift-left” initiative that entails implementing security checks in a software product as early as possible. With this approach, development teams can plan deployments efficiently because they can address the security risks that might disrupt the planned release timeline earlier. While connecting SDLC might seem like rocket science, or even expensive, it’s non-negotiable. For a start, you can take advantage of automation tools.   

What Are the Strategic Benefits of Implementing a Secure SDL for Your Business Products? 

A recent study by Wabbi estimates that businesses that adopt a secure SDLC process for continuous security can decrease vulnerabilities in their software systems by up to 50%. Besides this, there are other various benefits of implementing a secure software development lifecycle for your business products, including: 

Better security 

A secure SDLC framework ensures that businesses continuously monitor their software systems to reveal possible vulnerabilities and security lapses. You can then mitigate these risks before they actually happen to improve the overall security of the software product. 

Regulatory Compliance 

Various jurisdictions have laws and regulations that depict how software products should operate, to ensure that sensitive data doesn’t get into the hands of the wrong people. A sound software development security policy ensures that you stay on top of these regulatory requirements to avoid fines and penalties in the event of a lapse. 

Reduced Costs 

Taking a secure application development approach in your business allows you to pinpoint flaws at the early development stages. Fixing these flaws when developing can be less costly as opposed to mitigating them when the application is already deployed. 

Adopting a secure SDLC process in your software products also comes with several other side benefits, such as: 

  • Ongoing training for development teams on secure coding culture 
  • Better in-house security when leveraging customized, internal system tools 
  • Better customer retention due to improved security in your software products 
  • Consistent security awareness among team members 
cost of fixing flaw at different stages of SDLC

Although a secure development workflow might differ from one organization to another, a typical one consists of the same building blocks at different product development stages. To put it into better perspective, let’s look into a typical development cycle. 

Planning & Requirements 

Defining the application’s concept and its feasibility happens at this stage. Besides coming up with a formidable plan for the project, you can also write down its requirements, as well as allocate human resources at this stage. Most importantly, you should conduct basic security awareness training for all employees to inculcate a security mindset across the entire team. Typically, this stage involves: 

  • SDL discovery, which defined the security and compliance goals of the software product project at hand 
  • Security requirements at both technical and regulatory levels 
  • Security awareness training for all team members 

Architecture and Design 

You already have the project requirements and insights into the skills needed to implement the application design. The next stage involves modeling the application’s design, as well as its structure in different consumption scenarios. You can source any third-party components that can speed up the overall development process at this stage. However, it’s imperative to countercheck any security vulnerabilities in your go-to third-party component and make the necessary patches before they weaken the entire software product at a later stage. 

The basis of this secure SDLC process includes: 

  • Threat modelling to simulate various attack scenarios and their possible countermeasures 
  • Secure design, where you validate subsequent updates to ensure that they are in line with the set security requirements 
  • Third-party software tracking to seal any security loopholes that the bad guys can exploit 

Software programming 

The actual creation process of the software product happens at this stage. For instance, you can write the software product’s code and debug it before taking it to actual testing. Secure code development practices implemented at this stage include: 

  • Secure coding, where the talent team can follow an agreed naming conventions or checklist to avoid erroneous mistakes that can be costly, security-wise 
  • Static scanning uses code analysis tools to reveal any weakness in the code without necessarily running the application 
  • Code review, which is usually manual to flag any security vulnerabilities 

Testing and Bug Fixing 


You already have a solid code for the application and the design is also ready. You can proceed to test it both manually and automatically to find any bugs and fix them. Security-proof development includes various practices at this stage, such as: 

  • Dynamic scanning using software tools that simulate hacker attacks when running the application 
  • Following CICD best practices such as continuous integration, continuous delivery, and continuous deployment 
  • Penetration testing using a third-party service provider to iron out any issues that your in-house team might have missed 

Release and Continuous Maintenance 

The application is ready to go live and you can now release it for usage in different use cases and environments. New patches and versions can also be made available during maintenance. Customers may choose to switch to the upgraded versions or maintain the original ones. Nonetheless, the recommended SDL practices at this stage include: 

  • Deployment- you can take the continuous integration (CI) or continuous delivery (CD) approach to release your application at a greater speed and frequency by isolating faults and resolving them swiftly. CICD approach also maximizes faster mean time to resolution during ongoing maintenance.  
  • Environment management 
  • Incident response plan to give a procedure that your in-house team should follow in the event of a security breach 
  • Ongoing security checks to shield the application from newly designed hacks and vulnerabilities 

Secure Development Best Practices 

As the name suggests, secure development methodologies prioritize security over everything during the overall application development process. Prevalent methodologies employed by both established and upcoming software product companies include: 

Implement an agile approach 

agile methodology

This development methodology involves building a software product or application in small iterations, known as product cycles to enhance rapid production and constant revision. Typically, this approach prioritizes teams’ interactions over tools and processes and working application over endless planning and documentation. 

Continuous development and improvement 

This methodology consists of a closed development loop that focuses on improving work output throughout the building cycle. The end goal of this methodology is to optimize value from ideation to end-user application. Numerous steps are involved in the DevOps methodology, including palling, coding, building, testing, release, deployment, operation, and monitoring. 

Well-defined responsibilities 

This methodology vests the responsibility of IT security on every member involved in the application development. Typically, the approach entails fostering the organization’s security practices in the DevOps pipeline. The shared responsibility ensures that the team builds a security-proof application. 

How to Start with SSDLC 

SSDLC can be beneficial in many ways as described earlier. You can get started with this development approach in the following stages: 

  • Review your options for a secure development lifecycle and choose the one that works best for your application scenario. 
  • Conduct an architecture risk analysis to close any vulnerabilities as recommended by the provisions of the secure development methodology. 
  • Extend your research to other projects similar to your methodology and learn from action analysis to get it right the first time. 
  • Create a list of coding standards to follow.  
  • Conduct a full training on your in-house team and third-party software development partners to increase awareness about possible security vulnerabilities 
  • Leverage various software tools to automate as much of the development cycle as possible, such as static code analytics or dynamic testing tools to develop a stable build. 
  • Validate processes for security activities within your software security initiatives (SSI). 

Over to you 

Leverage this guide to get an in-depth overview of what SSDL is and implement the strategy in your next software development project. This approach will help you prioritize security concerns on an ongoing basis, as well as reduce unnecessary costs associated with unexpected security downtimes. At Symphony solutions, we help clients build premier digital solutions with all-around protection against cybersecurity vulnerabilities. Check out our projects and reach out for SSDL services and consultation.