Organizations often focus on release velocity—measuring success by lines of code and time-to-market. However, the true bottleneck isn’t speed; it’s substandard software quality. Every unresolved defect shifts engineering focus from innovation to firefighting, fueling technical debt and stalling product growth.
As noted in the Gartner® research, “According to the Consortium for Information & Software Quality (CISQ), the estimated cost of poor software quality in the U.S. has grown to at least $2.41 trillion, with the accumulated cost of software technical debt standing at about $1.52 trillion.” Gartner also states, “Companies with a strong culture of quality make 63% fewer mistakes overall and take 46% less time to fix these disruptions.”
Source: Gartner, Top Strategies for Improving Code Quality, Ross Power, Joachim Herschmann, 18 November 2024
GARTNER is a registered trademark and service mark of Gartner, Inc. and/or its affiliates in the U.S. and internationally and is used herein with permission. All rights reserved.
The shift to proactive application engineering starts with embedding quality from day one. In a Greenfield project, where everything starts fresh, Shift Left testing is easy to embed from day one. Greenfield projects allow a zero-defect mindset from day one—where quality isn’t tested in but built-in. But in a Brownfield project, with major changes in existing product, legacy systems, multiple integration points and technical debt, the approach has to be different—balancing quality without disrupting what already works. Many teams don’t realize this and treat both the same, leading to inefficiencies, reduced reusability and higher costs later. Let’s dive into why Shift Left isn’t one-size-fits-all and how strategies must change for Greenfield vs Brownfield projects.
Also Read: Continuous Testing: A Holistic Approach to QA
Greenfield projects
For Greenfield projects, Shift Left is about establishing a quality-first mindset from the very beginning and embedding the quality initiatives from the Requirement phase. A few key aspects:
- Requirements Validation – Ensure requirements are well-defined and validated upfront. Identify architecturally significant areas for design validation and non-functional testing.
- Design Validation and Reviews – Employ static code analysis tools to catch potential vulnerabilities and code quality issues early in the development cycle. Review and fix design flaws before development begins.
- Write unit and integration tests before or alongside coding to ensure early defect detection.
- Automate unit, integration, and system tests, prioritizing regression and sprint-level automation. Leverage service virtualization when needed.
- Continuous Integration (CI) – Implement CI with automated builds, tests, and deployments on every commit. Integrate static analysis, security scans, and feature flags.
Brownfield projects
Brownfield Shift Left testing prioritizes embedding quality strategically within an existing system undergoing change. It is about identifying critical areas for testing new features, integrations, and refactoring, with a keen focus on safeguarding existing functionality. This approach ensures stability and minimizes risk during system evolution, effectively managing change within the live environment.
Below are a few examples of Brownfield projects, each requiring a tailored Shift Left testing approach to ensure quality, reusability, agility, stability, a first-time-right approach, and a smooth transition without business disruption.
- Application Re-platforming, Migration or Re-engineering – Ensuring quality during platform upgrades, technology re-engineering, or migration to new stacks. Validates functionality, compatibility, and stability, including transitions from monolithic to microservices architectures.
- Code and Feature Enhancement – Adding new features or major code changes in live applications. Focuses on early defect detection, integration validation, and stability to prevent disruptions.
- API & Service Layer Expansion – Introducing new APIs and integration points into existing ecosystems. Ensures contract validation, security, interoperability, and backward compatibility across distributed services.
- Performance & Scalability – Optimizing infrastructure, tuning codebases and databases, and applying performance engineering to handle increased loads. Ensuring reliability, efficiency, and seamless scaling under peak conditions.
Also Read: How Digital Transformation is Driving the Scope of QE
Case example of a Brownfield Shift Left Success – Implemented Continuous Testing for a global hotel chain to enhance quality across web, mobile, and APIs. Apexon’s AI-driven assurance improved defect detection, scalability, and automation efficiency, delivering 40-50% efficiency gains, continuous automation execution, and early defect detection for seamless system evolution.
While Shift Left in Greenfield projects focus on a quality-first mindset, embedding quality engineering at every phase, Brownfield projects require a more holistic approach. Beyond integrating quality initiatives, the focus must be on identifying critical risks, conducting impact analysis, and maximizing reusability.
Time constraints are often tighter in Brownfield projects, making efficiency crucial. If enhancements are made to live systems, it is essential to ensure zero disruption to business-as-usual (BAU) operations. For system upgrades, end users will compare performance against the previous version, making stability, performance, and user experience key priorities.
Here are some critical aspects to focus on for Shift Left in Brownfield testing:
- Impact Analysis & Risk Management – Analyze how new changes affect existing functionality and prioritize high-risk areas for testing. For migration or upgrades, conduct pre- and post-migration comparisons to ensure a seamless transition.
- Regression Strategy – While automation is ideal for regression testing, categorize tests as repeatable and one-time executions. Balance manual testing with automation, focusing on APIs, service layers, and integrations to maintain stability. Leverage automation for repetitive tasks and manual testing for high-impact changes—ensures faster feedback, better risk coverage, and minimal disruption to live systems. If robust automation already exists for the customer, prioritize reusability and maximize Return on Existing Investments (ROEI).
- Performance, Scalability & Security Validation – Maintain baseline performance, test under expected and peak loads, and proactively address security risks to ensure system resilience.
Also Read: Rethinking Test Automation Strategy and Test Automation Transformation
The Human Element in Shift Left
A successful Shift Left implementation, especially in Brownfield environments, relies heavily on team collaboration and knowledge sharing. Establish clear communication channels between development, testing, and operations teams. Encourage knowledge transfer sessions to share legacy knowledge and best practices. Invest in training and upskilling programs to ensure team members are proficient in the latest testing tools and techniques. Create a culture of continuous learning and improvement, where team members are encouraged to share feedback and contribute to process improvements. In Brownfield systems, knowledge of system functionality resides with those who have worked on it for years, making knowledge transfer a key component.
Conclusion
Shift Left testing requires different approaches for Greenfield and Brownfield projects. For Greenfield, quality is embedded from day one through proactive validation. For Brownfield, focus on impact analysis, risk management, and protecting existing functionality. Success depends on understanding your context, fostering team collaboration, and committing to continuous improvement. When implemented correctly, Shift Left testing reduces defects, accelerates releases, and lowers costs—delivering quality at speed in today’s competitive digital landscape.
To learn more about Apexon, visit our Quality Engineering Services.
