There's a story by Bryan Cantrill [1] about how he went to Twitter to help them understand why it would take 400 milliseconds of compute to process a request (I'll leave the reveal to Bryan). Scaling horizontally is probably necessary for something the size of Twitter, but that doesn't mean that we can half-ass the code and just throw more machines at the problem. If we write code with a bit more mechanical sympathy and avoid the latest non-proven fads, we can surely write software that is 10x faster and requires much less scaling.