Hybrid Model for Monorepo and Polyrepo

Mix of Monorepo and Polyrepo in an Organization

Hybrid repository strategies combine elements of both monorepo and polyrepo approaches to take advantage of their respective strengths while mitigating their weaknesses. Here are some strategies for adopting a hybrid approach:

1. Monorepo for Core Shared Code:
• Use a monorepo for shared libraries, common components, and infrastructure code that are critical across various projects.
• This approach ensures consistent versioning and easy code sharing for foundational components.
2. Polyrepo for Project-Specific Code:
• Create separate repositories for project-specific code, applications, or services.
• Each project's repository contains its own codebase, dependencies, and version control, providing autonomy for project teams.
3. Dependency Management:
• Establish a clear and well-documented process for managing dependencies between the monorepo and polyrepos.
• Use dependency management tools like package managers (e.g., npm, yarn, or pip) or Git submodules to include shared code from the monorepo into the polyrepos.
4. Continuous Integration and Delivery (CI/CD):
• Implement CI/CD pipelines that build and test code from both monorepo and polyrepos.
• Ensure that changes in shared code trigger automated testing and deployment across relevant projects.
5. Release and Versioning Strategies:
• Define consistent versioning and release strategies for the monorepo and individual polyrepos.
• Document these strategies and ensure that teams follow them consistently.
6. Code Ownership and Collaboration:
• Clearly define code ownership and collaboration guidelines.
• Specify which teams are responsible for maintaining shared code in the monorepo and how they collaborate with project-specific teams.
7. Tooling and Automation:
• Invest in tools and automation to streamline the integration of code between the monorepo and polyrepos.
• Automate the detection and resolution of code conflicts and compatibility issues.
8. Documentation and Onboarding:
• Create thorough documentation to help new team members understand the hybrid approach and the workflow.
• Provide training and onboarding resources to ensure that everyone follows best practices.
9. Regular Communication:
• Foster open and frequent communication between teams working with the monorepo and those maintaining polyrepos.
• Hold regular meetings to discuss changes, updates, and challenges.
10. Monitoring and Metrics:
• Implement monitoring and metrics to track the performance and health of the hybrid setup.
• Use these insights to make continuous improvements.

Hybrid repository strategies can be a flexible solution for organizations with diverse needs. They allow you to balance the benefits of code sharing and consistency while providing project-specific independence and modularity. However, they require careful planning, documentation, and ongoing coordination to be successful.

 Ways for changes in monorepo to be notified to dependent projects hosted in polyrepo:

1. Automated Build and Deployment Pipelines:
• Implement automated build and deployment pipelines for both the monorepo and the polyrepos.
• Whenever changes are made in the monorepo, the pipeline should trigger builds and tests for the shared components.
• Upon successful build and testing, the artifacts can be published or made available for consumption by the projects in the polyrepos.
• The project in the polyrepo can be configured to automatically pull or update the shared components when new versions are published.
2. Dependency Management Tools:
• Use dependency management tools, such as package managers (e.g., npm, yarn, or pip), to specify dependencies on the shared components hosted in the monorepo.
• Whenever there's a new version of a shared component in the monorepo, the project in the polyrepo can update its dependency version.
• Regularly run commands like npm install or yarn upgrade in the polyrepo project to fetch the latest versions of dependencies for nest.js, node.js, express.js projects.
• Dependency management in Visual Studio typically involves the use of the NuGet package manager for .NET projects. NuGet is a package manager that simplifies the process of adding, updating, and managing third-party libraries and dependencies within your .NET projects.
3. Webhooks and Notifications:
• Set up webhooks or notifications in the monorepo's version control system or in your CI/CD platform to inform the polyrepo project when changes occur.
• These notifications can trigger actions in the polyrepo, such as initiating an update process.
4. Periodic Synchronization:
• Implement a scheduled job that periodically checks for changes in the monorepo and updates the polyrepo accordingly.
• This approach is useful when continuous integration or automated processes are not feasible.
5. Manual Triggering:
• Have a defined process for team members to manually trigger updates in the polyrepo project whenever they make changes to shared code in the monorepo.
• This manual step ensures control and awareness of when updates are applied.
6. Change Logs and Release Notes:
• Maintain detailed change logs and release notes for the shared components in the monorepo.
• The polyrepo project can periodically check these logs to determine if there are new updates or changes it needs to incorporate.

The approach you choose will depend on your specific use case, tools, and infrastructure. Many organizations combine multiple methods to ensure that polyrepo projects stay up to date with changes in the monorepo. Regardless of the approach, clear documentation and communication are essential to keep all team members informed about the processes and responsibilities for managing dependencies between the monorepo and polyrepos.