At another job, at a financial firm I got a big bonus after I went live on November 28th with an upgrade that let a system 10x their max throughput, and scaled linearly instead of being completely stuck. at their 1x. Median number of requests per second received in dec 1st? 1.8x... the system would have failed under load, causing significant losses to the company.
Prevention is underrated, but firefighting heroics are so well regarded that sometimes it might even be worthwhile to be the arsonist