With software delivery timelines shrinking, teams are looking for ways to move faster without compromising quality or security. In our webinar, TSDD: Shifting Security Left Through Test- and Security-Driven Development, TestRail Solution Architect Chris Faraglia and PreEmptive & Kiuwan Solution Architect John Brawner break down how teams can bring testing and security into the development process earlier—and why that shift leads to more predictable, more resilient releases.
Here’s a closer look at what they covered.
Why release agility is harder than it looks
Many teams today are following Agile or DevOps processes but still struggle with delivering reliable, on-time releases. The problem often isn’t the methodology—it’s the execution, especially when it comes to timing.
Testing is frequently delayed until the tail end of the development cycle after features are fully integrated. Security checks usually happen even later, often during a last-minute hardening sprint. If issues are found at that point, there’s little time left to fix them—which delays releases or, worse, allows risks to go unresolved.
When priorities shift mid-cycle, testing and security efforts are usually the first to get cut or deprioritized to meet deadlines. That’s how technical debt and risk accumulate.
How program increments bring structure and flexibility
One practical solution is to adopt program increments (PIs)—8-to-12-week planning cycles drawn from the SAFe framework. These help teams stay focused on delivering high-value work in small, testable chunks. Even without formal SAFe implementation, program increments can help teams:
- Deliver features in smaller, more manageable pieces
- Measure progress more consistently
- Make changes without derailing the entire release
It’s a flexible way to keep delivery on track while creating room for integrated testing and security throughout the cycle.
“Fast Flow” and shifting left: Building quality from the start
One of the central goals of TSDD is enabling fast flow—the ability to deliver changes to production quickly and confidently. But fast flow doesn’t mean cutting corners. It means removing friction from the development process by catching issues earlier and building quality in from the start.
That’s where the concept of shifting left comes into play. Instead of waiting until the end of the release cycle to validate code, teams move testing and security activities earlier in the software development lifecycle.
TSDD supports this shift by encouraging a proactive mindset:
“Testing and security requirements are defined and even executed before development begins, ensuring functionality and security are built into the software from the start.”
By making test cases and security expectations part of initial planning, and integrating tools like SAST and SCA early, teams shorten feedback loops and minimize rework. That allows for faster, safer releases.
TSDD: Start with testing and security
At its core, Test and Security-Driven Development (TSDD) is about aligning teams on quality and security requirements before development even starts. It’s more than just writing tests first—it’s about building a shared understanding across developers, testers, and security engineers.
This mindset shift encourages teams to ask critical questions early on:
- How will we test this?
- What are the security implications?
- Are we building something that’s both testable and resilient?
With those answers in hand, teams can reduce surprises and build with confidence from the start.
Security-focused TDD in practice
Consider a REST login service. Before it’s even built, a team might write a Postman test simulating a login attempt with expired OAuth credentials.
That test would:
- Check for the correct HTTP response code
- Ensure no sensitive data is returned
- Validate that a clear error message is provided
This kind of negative testing is especially useful for validating known risks—such as those outlined in the OWASP Top 10. By writing these tests early, teams avoid discovering critical issues late in QA.
How DevSecOps connects the dots
TSDD fits naturally within a DevSecOps approach, where security is embedded throughout the entire development lifecycle.
Key practices include:
- Risk assessments and threat modeling
- Secure coding standards to prevent vulnerabilities
- SAST (Static Application Security Testing) to scan code before it’s built
- SCA (Software Composition Analysis) to evaluate third-party packages
- Runtime tools like RASP (Runtime Application Self-Protection) and WAFs (Web Application Firewalls) to monitor production
With up to 80% of application code often coming from open-source components, SCA tools are critical for managing risk and ensuring license compliance.
Why automation and feedback loops matter
Automation plays a critical role in making TSDD scalable. Once tests and scans are in place, they should run automatically—ideally with every pull request or commit.
This approach creates a continuous feedback loop that:
- Surfaces bugs and vulnerabilities earlier
- Reduces manual testing bottlenecks
- Enables quicker decision-making during development
And like any strong DevOps practice, continuous improvement is key. Teams should regularly evaluate what’s working, what’s slowing them down, and how to improve their testing and security posture over time.
Image: Managing testing and quality workflows across teams? TestRail helps QA and DevOps teams plan, organize, and track tests to ensure complete coverage and faster releases.
Bringing it all together
TSDD isn’t just a methodology—it’s a cultural shift. It asks teams to treat testing and security as design inputs, not delivery checkpoints. And when these practices are embedded from the beginning, the result is more stable releases, fewer delays, and a team that can move fast without compromising safety.
If your organization is looking to deliver software faster without sacrificing quality or security, TSDD is a smart place to start.
Here are a few ways teams can continuously improve their testing and security posture:
- Early Test Creation: Prioritize writing tests before coding begins. With TDD, functionality is validated up front, and security requirements can be tested and enforced from day one.
- Automated Early SAST Scanning: Integrate Static Application Security Testing (SAST) into your early development workflow. Scanning code as it’s written helps catch vulnerabilities when they’re easiest to fix.
- Continuous Security Feedback: Don’t wait until the end of the sprint to run security checks. Instead, build continuous feedback loops into your pipeline with tools that automatically surface issues during development.
- Foster Cross-Team Collaboration: Keep lines of communication open between developers, QA, and security. Shared goals and early alignment help everyone deliver higher-quality work, faster.
By making continuous improvement part of your development culture—not just a one-time initiative—your team can build software that’s not only faster to market but built to last.
Want to dig deeper? Watch the full webinar on-demand to hear more examples and get practical tips on applying TSDD in your own organization.
