[pjmlp]

Is it possible to achieve 20 percent improvement in perf and engagement by improving existing code instead of fully rewriting it in another technology stack?

What would be the monetary cost of such decision versus the monetary cost of the one taken?

Which approach would achieve the same value of 20 percent improvement in perf and engagement with lower amount of money being spent?

[ng12]

Did you read the article or just the word "React"? They're incrementally migrating, not fully rewriting the application.

[pjmlp]

Yes I did, and did not saw the business case (monetary) in the decision.

[ng12]

Well the article is primarily about the technical implementation, not the business rationale. But they still mention the main reasons: engineer productivity, community support, and performance gains. All of those translate to money.

As someone who used to work on large Backbone apps I agree that it's a huge drain on developer productivity -- hard to add features, hard to test, lack of standards, etc. Not to mention the recruiting problem: I would never accept a job offer to work on a Backbone app again.