Times change. IT systems have brutally invaded our lives, and software eats humanity for breakfast. In the meantime we carry 8 cores and 8 GB RAM in our pockets. The AMD presented a 12-core processor on the so-called consumer market, and Gmail is still stuck and sluggish when it is scrolled through emails. To edit a text file, we need 2 GB of RAM, and an application, which performs the same functions as IRC in the 90s, devours any amount of CPU and memory. And nobody cares. Hardware is cheaper than programmer’s time… right? Since such words, like cloud or serverless, have dominated any architectural discussion, the lie repeated for years has become truth. During the presentation, I would like to share with you the answer to the question posed in the title of the presentation: is efficiency quality? How to ensure the performance of your systems? Who is responsible for all this? (will we sadly discover at the end that the HR department?)? How does all this relate to Krakow’s smog? How to start with performance testing, what techniques, tools and skills do we need to possess? And why “performance man” is the best profession in the world?