An article[1] from 2018 mentions 70 engineers. Let's assume 50% growth yoy which puts them at 157 engineers now. Making another assumption that only 20% of these engineers are productive which gives us 31 engineers. That's 1600 microservices for 31 engineers.

That sounds large but if you have 1600 microservices you are _most likely_ writing a single service where you'd normally write a class. Does 50 classes per engineer sound like a lot? Sure does but they didn't create this infrastructure out of thin air - this is an accumulation of many years. For sake of the arguments let's say 2 years. Across 24 months that's only 2 microservices per developer per month.

Not unthinkable, and this is assuming only 20% of their engineering force is actually productive.

[1]https://monzo.com/blog/2018/06/27/engineering-management-at-...