There was a time in the early days of the internet and the app economy when scale was a challenge that only a select few really had to fret over. The term “web scale” was coined to address the early challenges of companies like Amazon, Google, and Microsoft, and later addressed the architecture work taken on by Facebook, Netflix, and others to first reach massive volumes of users. But now, 25 years from the start of digital transformation, nearly every company sees massive concurrency and increasing demands on their applications and infrastructure. Even the smallest start-up must think about scale from day one.

Modern applications are overwhelmingly data-intensive. We expect highly dynamic, personalized experiences to be available instantly. These applications are increasingly global in nature, as well - think Spotify, Uber, or Square - and have complex needs in trying to balance both consistency and locality. Our applications have become ever more complicated with ever more components that must be managed and scaled.

Further challenging us, users have come to expect absolutely flawless experiences. There is zero tolerance for latency or downtime, even under the heaviest workloads. In this context, your most successful moments - when your application sees rapid growth or when your content goes viral on social media - have the potential to become your worst day.