Edit: I think the article also misses one of the most important ways to release pressure. And that is scaling throughput either horizontally (e.g. by adding more servers) or vertically (e.g. by optimization of software)
The first is not always possible (not all systems are elastic or can be, due to money/resources), and the second is not really a way to handle back-pressure. You could have back-pressure in the most optimized system.
Note that I meant "handling (forward) pressure (or preventing back-pressure) can be done by simply having your system be performant enough. Of course this is not a dynamic property you can adjust at runtime, just wanted to add for the sake of completeness, because it should be part of the mindset. Sometimes a database falling over simply needs a few queries optimized.
> You could have back-pressure in the most optimized system.
Most batch processing systems. But you don't want back pressure in interactive or real-time systems, like graphics, gaming, audio, cars, planes, or even just real time collaboration systems (e.g. Figma). In all these cases back pressure is to be avoided.