Ask HN: Often have you had to re-write a legacy front end application

How often have you needed to modernize a legacy frontend application and re-build them using a more modern technology/framework like React/Angular etc.?

At my current job, I have to migrate a JQuery dashboard to React. I was wondering what other people's experience has been in this regard.

What were some of the pitfalls that I should look out for?

If you ever had to do it, what was the most painful part of this migration?