[rahilsondhi]

Using npm alone is like using bundler without a Gemfile.lock. If one person does `npm install` today, and a new teammate does `npm install` in a month, the new teammate will install different versions. With yarn, there is a yarn.lock to make sure everyone gets the same versions when they run `yarn install`.

Also, yarn is way faster.

[eggie5]

Thanks for the analogy. I am now update-to-date w/ 3 years of JS churn :)

[paulddraper]

There is npm shrinkwrap, but the yarn folks will tell you yarn is better.

[sergiotapia]

There is ${some_random_lib} to solve this problem? Yawn! Use Yarn, it comes baked in.