Choosing the Right Type of Source Code Repository for Your Project
Allison Bokone
·
Last updated on September 16, 2024
When managing a Git source code repository, teams typically choose between three approaches: monorepo, polyrepo (or multi-repo) or hybrid. Each has its own strengths and challenges and selecting the right one for your project is a crucial first step. In this article, we’ll dive deeper into the differences between these code repository types and help you understand which might be the best fit for your team’s needs.
A source code repository, or repo, is shared storage that is critical for software development. Repos allow teams to track and version their code changes, ensuring project status and history are saved in a location accessible to the development team. The type of repo setup you choose can impact the way your engineers work and collaborate. This article gives an overview of three ways of configuring your repositories. If you’re just learning about version control, you can read more about version control tools in these articles: Popular Source Code Management Tools and How They Solve Problems and How to Choose Version a Control System
A monorepo is a single source code repository that contains all the code for a project, product, or company. Microservices, UI, and libraries all get stored in directories under the same repo. This structure can simplify the onboarding process for new employees, making it easier for them to set up their environment and understand where to begin. When you clone a repo, everything needed to run any code in the project will be included. With everyone working out of the same repo, it’s also likely that the teams will share development methodologies, branching strategies, and development tools and processes.
Another benefit to this approach is that it is easier to identify code dependencies and track bugs that impact multiple areas because everything is stored in one location. Every developer will have all the related code files and if they are well organized it should be easy to locate impacted libraries and identify which developers need to be involved in bug fixing.
A monorepo can also make software testing and automation easier. According to Accenture, it’s much easier to run back-end and front-end testing for full-stack projects locally with a monorepo setup because the paths and file structures are known. This allows a developer to run a local script to start each service locally. With a monorepo it’s also possible to run a full suite of tests any time a library is changed, quickly flagging any breaking changes to developers.
Of course, downloading the entire repo can be time-consuming and incorporating dependent breaking changes more often can slow down development. Kinsta also points out that tags are applied to all within the monorepo, which means libraries that have not changed will get new version numbers for every release.
A polyrepo is where code is organized logically across multiple repositories. Libraries, microservices, and reusable code are each contained in their own repo. This type of granular repository structure helps solve several of the challenges seen in monorepos. Teams can work independently from each other without triggering version updates or breaking changes that must be fixed immediately.
Individual microservices can be updated, allowing some teams to iterate and release faster than others without causing conflicts or delays. It’s also easier to configure CI/CD and targeted automated testing for each component because you don’t have to specify the subset of files to test, you can simply configure your build and release pipeline for each repo.
Teams that have dependencies on changed libraries will still have to stay in sync with new versions but this may not be as obvious in a polyrepo setup. Teams must still communicate with each other to understand how different source code repository releases impact other parts of the product and ensure there is a plan for keeping everyone up to date on the latest releases.
Companies may also need to put more of an emphasis on software development processes and tools if they want to create a shared culture. While allowing teams to adapt and modify processes to work best for their scenarios is empowering and easier to accomplish with a polyrepo setup, teams can quickly diverge and create very different working environments without some shared practices. A lack of central process can make it more difficult for new employees to get up to speed and make it harder for employees to switch between teams.
For this reason, regular communication, sharing of lessons learned, and coordinated process improvements are needed to help teams stay in sync on the most important parts of their software engineering processes. This way, engineers can successfully work cross-group and move around the company.
If your team requires the capabilities of both monorepos and polyrepos you can leverage hybrid options to meet your needs.
Poly-as-mono is where teams work in multiple repositories, but use tools to automate synchronization so that everyone has the full codebase at all times. This gives teams the benefits of a monorepo with more flexibility when it comes to independent development.
Mono-as-poly is the opposite approach for when teams want to work in a single monorepo but require more granular code repositories for deployments. There are scripts and tools to help teams split their codebase according to what’s in individual release packages.
| Category | Monorepo | Polyrepo |
| Code Organization | All code, including microservices, UI, and libraries, is in one repository. Simplifies dependency management and bug tracking. | Code is organized across multiple repositories, with each component in its own repo. Enables faster independent iteration. |
| Onboarding & Collaboration | Easier onboarding as everything is centralized, with shared tools and processes across teams. | Requires more communication and coordination, as different teams may use varied processes and tools. |
| Development Speed & Flexibility | Shared dependencies can slow down development when breaking changes affect multiple areas. | Teams can release components independently, reducing the risk of breaking changes impacting others. |
| Testing & Automation | Easier to run comprehensive tests across the entire codebase but can be time-consuming. | Allows for more focused and faster development cycles with targeted CI/CD and automated testing for specific components. |
| Versioning & Release Management | Version numbers apply to the entire repo, potentially causing unnecessary version bumps for unchanged libraries. | Granular versioning per repo prevents unnecessary updates across other parts of the project. |
Overall, the choice between monorepo vs polyrepo depends on the specific needs of the project and the development team’s preferences for collaboration, speed, and flexibility.
Assembla is the only cloud solution that supports Git, Perforce, and Subversion. This gives teams the flexibility to organize development work in the way that works best for your company while still working in a shared environment that enhances collaboration and communication.
To learn more about the benefits of cloud-based version control, check out How Enterprise Cloud Version Control Improves Efficiency. If your team is trying to decide which version control management software to use for their next project, these articles offer a detailed comparison of the options Assembla supports: Perforce vs Git: A Comprehensive Comparison, Perforce vs SVN: What’s the Difference?, and SVN vs Git: Finding the Best Fit for Your Development Workflow.
If you’d like to explore cloud-based version control, start a free 14 day trial of Assembla. Our team would love to talk with you about how Assembla can help your team get set up for success.
