DoS yourself in production every night to prove you can take it
At JUST EAT, we haven't had an embarrassing performance regression that we haven't noticed and put right on the same day we deployed it - for over two years now. We also haven't been taken down by unexpected load.
We have around 150 engineers deploying tens of times a week across around 120 different components in production. In 2014, we pushed more than 800 discrete changes and coped with around 50% more traffic as we grew. Our uptime has... gone up.
We don't have engineers run a performance test before we release have engineers run capacity tests every month or so when we remember to Instead, we do something a bit different...