- Build some webapp and get it working correctly in Chrome
- Test on Firefox. It works 90% of the time. 9% of the time it's relatively easy to support. 1% of the time it isn't worth the hassle.
- Test on Edge. It works 80% of the time. 10% it's an easy enough fix. 10% you have to move heaven and Earth to fix and when you contact Microsoft, they know about the issue but won't do anything to help.
- Test on IE. It works 60% of the time. The other 40% of the time you start looking for a new job so you don't have to write the same code a second time for IE.
