Name: Video recording for Monorepos in the JS world - Codementor Events
Uploaded: 2022-05-03
Description: This talk will help you get familiar with the essential tools of monorepo management.

## About the talk

What is a monorepo? Monorepo is a practice that helps us organize multiple projects into a single git repo. Monorepos can help teams save time on syncing and spend more time on development. Not only so, monorepos, as a single source of truth of every dependency, can increase visibility and consistency. Here are a few time syncing tasks that monorepos can resolve:
- Pulling and pushing from git repositories across many folders on your PC just to run the project
- Bumping versions on different npm packages
- Figuring out where to run the "yarn link" command and when to build each package


### This talk will cover
- The basic terms and project evolution: monolith, polyrepo, & monorepo
- Basic concepts related to monorepos: npm and yarn links, workspaces, Lerna, and NX
- How open-source projects use Lerna to manage their monorepos and simplify workflow
- How enterprises use NX to increase build times and simplify their internal workflows

technical events about the web like JavaScript, web3

Web Development

### What are some basic concepts to know before getting started with monorepos?


The basic concepts to understand include project/package, repository, monolith vs. microservices, polyrepo, and monorepo. Projects and repositories are self explanatory and require no further explanation. 


A monolith is a server or UI app that uses a single huge codebase. The advantages include it’s easy to set up, to debug, and great for small applications. The disadvantage is that every time you add something small, you’ll have to test, build, deploy, and run a huge codebase. It’s harder to test specific features, it’s expensive to build unchanged features, and deploy and run a single entity. The disadvantage with running the entire code base is when you’re scaling, when you have many instances with a single huge codebase and spin up additional instances, it will be hard to profile and know exactly where the bottlenecks are. However, if you have microservices, and you see that a service suddenly spins up many instances, it’ll be much easier to identify. 


A polyrepo is when you split a monolith into different projects. The most intuitive way is to create and manage a git repo for each project. The advantages of polyrepo include it’s a very intuitive approach, there is no tooling or expertise required to set up, and each repository has its own CI/CD. The disadvantages mostly revolve around the difficulty or maintenance. It’s hard to manage internal and external dependencies, the onboarding is slow, and the dependencies are high. 


### What is a monorepo and the JS monorepo ecosystem?


A monorepo is a repository that includes many projects and packages. The classic monorepo journey involves linking the poly repo repositories with an npm link, merging to a shallow monorepo with lerna, and deepening the projects with libraries with nx. 


Linking packages are just symlinks that are managed by npm or yarn. It’s very useful because you’re able to link external libraries that you work on locally and easily connect dependent repositories on a polyrepo. The con is that it doesn’t scale for running many projects. To tackle the challenge, you can use Lerna import, a widely used toolset that is no longer maintained, to convert polyrepos into monorepo. The way to think about lerna is that it’s a single entity with different hands and many different capabilities.

CEO at appk and a proud codementor


Adam Genshaft  

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This talk will help you get familiar with the essential tools of monorepo management.

Video recording for: Monorepos in the JS world

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