Building a 300 miles per hour production car is hard. Speed is not a linear measurement, even though you think of it that way. Taking a car from 150mph to 300mph requires eight times more power, or O(n^3) in our language, which is incredibly challenging. And there is a lot more to it than power.
Pushing the maximum of a single replicated RabbitMQ queue from 25k messages per second to 1 million took a lot more than better algorithms. And no, we didn't change the programming language or the code VM. In order to understand this, we first need to have a clear picture of the building blocks and what the limits are. Next, we look at the solution, and conclude by identifying the upcoming developments in the wider technology sector. They will help us build faster and more efficient queueing systems.