[margorczynski]

What you're speaking of is a need/usability-based design and extension where you design the solution with certain "safety valves" that let you scale it up when needed.

This is in contrast to the fad-driven design and over-engineering that I'm speaking of (here I simply used ES as an example) that is usually introduced because someone in power saw a blog post or 1h talk and it looked cool. And Kafka will be used because it is the most "scalable" and shiny solution, there is no pros-vs-cons analysis.