[dean]

The conventional wisdom in software development is to never rewrite your application from scratch. Typically it's much more difficult than you thought it would be, and it takes too long. Meanwhile, competitors pass you by (remember Netscape?). Just wondering how you came to make the decision to do this, and what, if any, concerns came up along the way?

[dahart]

The blog post mentioned getting test coverage before starting: https://code.facebook.com/posts/1716776591680069/react-16-a-...

I always remember how the SQLite author Richard Hipp talked about being able to rewrite major chunks of the SQLite engine due to their test coverage. Their testing page currently says they have 730x more test code than core library code. https://www.sqlite.org/testing.html

[brokencode]

The conventional wisdom applies to large, complicated software. The source for React comes in at around 109kb now. That couldn't be more than 10-20 thousand lines of code, which is quite small.