> Every line of code we write today will end up as someone’s legacy code.

RUM Code coverage

FES javascript instrimentation visualization

- [Instrument JavaScript code – Roman Liutikov – Medium](https://medium.com/@roman01la/instrument-javascript-code-ed9aca423e2a)
- [Raiders of the Fast Start: Frontend Performance Archaeology - Perform…](https://www.slideshare.net/KatrinaSylorMiller/raiders-of-the-fast-start-frontend-performance-archaeology-performancenow-conference#94)

- [uncss/uncss: Remove unused styles from CSS](https://github.com/uncss/uncss)