Today's 30-sec SRE is on scale. The term "scalability" is frequently mentioned, particularly in the context of cloud and cloud-native applications. While many recognize its importance and need, there is often a lack of clarity about its precise definition. Back in the day, in my computer science class, we examined various sorting algorithms and calculated their scalability using Big-O notation (or better: Landau notation). This notation was a valuable tool for evaluating the efficiency of algorithms, but unfortunately, its rigorous application is often missing in today's discussions about scalability.