Single Repository (Monorepo)

Pros:

• Knowledge Sharing

• Common styles and themes

• Easier for team members to switch projects

• Easier to track dependencies between projects

  • Example: I don't have to find the repository where a particular service lives

• Engineers can see work and progress of other people

• Engineers are not siloed

Cons:

• Possibility of a lot of noise/overheads

Examples:

• Angular

• Babel

• Ember

• Jest

• React

Tools:

• For JavaScript/Node.js: Lerna​

Alternatives:

• Consider having fewer repos, but larger

Examples:

• Facebook

  • Actually has many repos, but few (say less than 10)

• Google

  • One huge repository built by Google

• ​Microsoft's Azure​

• Twitter

Multiple Repositories (Multirepo)

Pros:

• Independent teams and styles

Cons:

• Problems with coordination

• Limits knowledge sharing across repositories

• Context switching between work across repositories

• Hard to enforce styles

• Smaller repos, but many

• Engineers can be siloed

• Hard to track depedency management

Common in:

• Microservices

• FaaS / Serverless

Examples:

• Amazon

• Skype

Also known as:

• Polyrepo

Comparison Matrix (Software Architectures vs Repository Styles)

A: Monolithic and Monorepo

Pros:

• Knowledge sharing

B: Non Monolithic and Monorepo

C: Monolithic and Multirepo

D: Non Monolithic and Multirepo

Cons:

• Increased operaitonal complexity and cognitive load