Mastering the Shift-Left Approach: Early Testing and Quality in Software Engineering

One Paradigm shift came in the Software Development when the Agile Manifesto was introduced, reshaping how teams approached software projects. Agile prioritized customer collaboration, iterative development, and flexibility. Today, Agile is a cornerstone of modern software development. But software development is an ever-evolving field, and one of the most recent transformative shifts to emerge is the ‘Shift Left’ approach. Much like Agile, Shift Left challenges traditional practices and brings a new perspective to the development process.

It is important to understand how Shift Left approach can help your project and how you can bring change to your existing process. This brings to million dollar question – What is Shift Left approach and how does it help?

What is the Shift Left Approach?

Traditionally, development teams would focus on coding and development first, leaving testing, security checks, and bug fixes for later stages. Consequently, it’s not uncommon to encounter critical application bugs, security vulnerabilities, or performance issues quite late in the development process. Addressing these issues at such a late stage incurs substantial costs and puts you as Development Managers in a challenging position when responding to stakeholders’ inquiries. It also raises questions about the effectiveness of your development processes and could potentially lead to unwarranted scrutiny.

Shift Left, however, advocates moving these critical activities earlier in the development process, even before the coding phase begins. The idea is to catch and address issues as early as possible, reducing the cost and time associated with fixing them later.

Let’s delve into some of the different types of Shift Left approaches that have gained traction in the industry:

1. Shift Left approach in Testing – This can be achieved by implementing any or all of following ways:
   • Prioritize testing early in the development cycle, including unit testing, integration testing, and continuous testing.
   • Implement test-driven development (TDD) practices where tests are written before the code.
   • Dev should work closely with Test team during development . QA should not wait for Dev to finish and then start testing. They can together ensure that the Test Charter/Cases are shared and incorporated as Unit/Integration Test if possible.
2. Code Review and Static Analysis Shift Left:
   • Use Resharper of SonarLint static analysis tool integrated with IDE.
   • Incorporate code reviews and static code analysis into the coding phase. There are many popular static code analysis tool like SonarQube. You can add SonarQube scan as part of Pull Request (PR) pipeline. Only when scan is successful should you allow PR to be approved. You can either add SonarQube build breaker task (if using community edition of SonarQube) or can add SonarQube verification as part of “Status Check” in Branch polices like in the case of Azure DevOps.
3. Performance Shift Left:
   • Start performance testing and optimization efforts early in the development cycle.
     • Use Profiling tools integrated with the IDE while developing. Test for performance while development.
     • Set up your pipelines (use tool like JMeter) to test for performance of your endpoints and Web pages daily as part of daily (nightly) builds.
     • Benchmark your endpoints for response time and fail the endpoints if it crosses the SLA.

4. Documentation Shift Left:

• Begin documenting code, architecture, and system designs from the early stages of development.
• Maintain up-to-date documentation throughout the project.

5. User Experience (UX) Shift Left:

• Involve UX designers and conduct usability testing early to ensure a user-friendly interface.
• Prototype and iterate on the user interface before development
• Use accessibility feature of browser to test your application for accessibility while developing.

Like a true Manager, now the questions should arise, what impact does it have on the Metrics?

Here are different Dev metrics that can be influenced by adopting the Shift Left approach:

1. Total Bug Count: Shift Left encourages early and continuous testing, leading to the detection and resolution of bugs and issues at earlier stages of development, reducing the time required for debugging.
2. Defect Density: With early testing and quality checks, Shift Left can lead to lower defect density, indicating higher software quality.
3. Code Review Efficiency: By conducting code reviews earlier in the process, you can identify and address coding issues more efficiently, reducing the time spent in code review cycles.
4. Deployment Frequency: Shift Left, when combined with CI/CD practices, can increase deployment frequency, allowing for more frequent and reliable releases. Remember this is one of the DORA Metrics.
5. Lead Time for Changes: The approach can reduce lead time for changes, as issues are detected and addressed early, leading to quicker turnaround on feature requests and bug fixes. This is another key metrics and also one of the DORA metrics
6. Mean Time to Recovery (MTTR): With early identification and resolution of issues, the Shift Left approach can reduce the mean time it takes to recover from failures or outages.This is another key metrics and also one of the DORA metrics.
7. Test Coverage: Early and continuous testing increases test coverage, ensuring that a higher percentage of code is tested thoroughly.
8. Security Count and Severity: By integrating security testing and reviews early, Shift Left can help identify and mitigate security vulnerabilities before they become critical issues.
9. Technical Debt: Shift Left can help manage technical debt by preventing the accumulation of coding and architectural issues that can lead to higher maintenance costs.
10. Release Confidence: With Shift Left practices in place, development teams can release software with greater confidence in its quality and stability.
11. Risk Mitigation: The approach helps mitigate project risks by identifying and addressing potential issues and challenges at their inception.

Please comment and let me know on what you think about this article? Share your experience on development processes changes or initiatives you have taken in your organization and how it helped your project.