Introduction

As Pega Platform continues to evolve, its recommendations for application structuring and development workflows have become increasingly aligned with modern DevOps principles. A key shift in best practice, particularly from Pega Platform, is the formal recommendation to establish a dedicated Testing Application. This approach significantly improves isolation, governance, and integration with Continuous Integration/Continuous Delivery (CI/CD) pipelines.

This article outlines the latest best practices for structuring your Pega applications, focusing on the essential framework vs. implementation layers and the modern three-layer application environment structure required for a robust, scalable, and maintainable Pega solution.

1. Framework vs. Implementation Applications

The foundation of a well-structured Pega solution remains the strategic use of the **Situational Layer Cake™** architecture, which promotes reuse and specialization.

Key Principle: Avoid creating unnecessary frameworks. A single, well-designed Implementation Application is often the most agile starting point. Frameworks introduce complexity and should only be adopted when the benefits of reuse outweigh the overhead of maintenance.

2. The Modern Three-Layer Application Environment Structure

To fully support agile development, robust testing, and automated deployment via Deployment Manager, Pega now recommends a clear separation of concerns across three distinct application layers: Development, Test, and Production.

A. Development Application (The Active Workspace)

This application is the primary workspace for developers.

• Purpose: To manage features and changes that are actively in progress.
• Structure: It is built on the **Test Application** (or the Production/Target Application if a Test App is not yet established).
• Rulesets: Contains unlocked Rulesets for active development work.
• Workflow: Developers log in via a dedicated Access Group. Once work is complete, changes are merged into the Production/Target Application's Rulesets.

B. Testing Application (The Quality Gate)

This is the critical new layer that ensures quality and isolation. It is a **separate, dedicated application**, not merely a set of testing rulesets within the main app.

• Purpose: To house and execute all automated and manual test cases (e.g., Pega Unit Tests, Scenario Tests) without polluting the core business logic.
• Structure: It is a **locked application** built on the **Production/Target Application**.
• Rulesets: Contains dedicated, separate Rulesets solely for test assets.
• Benefit: By being a separate application, it can be deployed to a subset of environments and its assets can be managed and promoted independently by Deployment Manager, acting as a dedicated quality gate in the CI/CD pipeline.

C. Production/Target Application (The Deployable Core)

This application represents the stable, deployable version of the business solution.

• Purpose: To contain the core, validated business logic ready for deployment to higher environments (Staging, Production).
• Structure: It is the base application that the Development and Testing applications are built upon.
• Rulesets: All Rulesets are locked. It contains **no** development-in-progress or testing-specific rulesets.

3. CI/CD and DevOps Alignment

This three-layer structure is essential for modern Pega DevOps, particularly when using Deployment Manager 5.

### A. PegaDevOpsFoundation

To enable seamless pipeline integration, the PegaDevOpsFoundation application must be added as a built-on application to your Production/Target Application. This component provides the necessary capabilities for Deployment Manager to execute pipeline tasks and integrate with Dev Studio and App Studio.

### B. Application Packaging and Versioning

Pega recommends packaging the entire application via the Product Rule for deployment. This practice offers several advantages:

Consistency: Ensures that every environment receives the exact same, validated set of rules.

Recoverability: Allows for convenient recreation of an environment if corruption occurs.

Simplicity: Reduces the burden on developers to manage complex delta deployments, as Pega Platform automatically handles the difference between versions.

For application versioning, the best practice is to use Lock and Roll for small patches and Skimming for major or minor version increments, ensuring a clear version history and maintainability.

## Conclusion

Adopting the modern Pega application structure—characterized by the clear separation of Framework and Implementation layers, and the crucial addition of a dedicated Testing Application is a critical best practice. This layered approach ensures scalability, maintainability, and compliance with Pega's latest guardrails, enabling smoother CI/CD integration and significantly reducing deployment risk.

References

[1] Pega Documentation: Best practices for application configuration - Deployment Manager 5

https://docs.pega.com/bundle/deployment-manager/page/deployment-manager…

Details the recommended three-layer application structure (Development, Test, Production), the role of PegaDevOpsFoundation as a built-on application, and best practices for packaging entire applications via Product Rule for deployment.

[2] Pega Academy: Application Structure

https://academy.pega.com/topic/application-structure/v5

Covers the foundational concepts of application organization, the Situational Layer Cake™ architecture, and Framework vs. Implementation application design patterns.

[3] Pega Documentation: Testing Pega Applications

https://docs.pega.com/bundle/platform/page/platform/devops/testing-pega…

Explains the need for dedicated testing assets, automated unit testing using PegaUnit, scenario testing, test automation setup, and the role of testing in CI/CD pipelines.

[4] Pega Academy: Application Versioning

https://academy.pega.com/topic/application-versioning/v6

Provides comprehensive guidance on application and Ruleset versioning strategies, including when to use Lock and Roll versus Skimming for version management.

[5] Pega Academy: Locking and Rolling Ruleset Versions

https://academy.pega.com/topic/locking-and-rolling-ruleset-versions/v2

Details the Lock and Roll process for creating incremental patches and minor versions, including best practices for version control in the DevOps pipeline.