[overlordalex]

Even then this is risky - if that developer is hit by a bus do you throw the service away and have another developer write it again?

We recently had an interview candidate say this when we questioned the wisdom of having over a thousand microservices: some in languages that only the one developer maintaining them used! For me this is insane, but I digress

Monzo says that they have 800 people, and 1500 services. If we're generous and say 500/800 are developers, then each developer is responsible for 3 services! A team of 6 would have 18 projects in their domain.

[rkangel]

There is a classic tradeoff here between top down organisation dictates giving consistency vs engineering independence giving flexibility.

Two organisations that I know of who favour the latter are Spotify and Netflix. It has benefits - different languages are good for different jobs and engineers like to be able to choose their tools.

It would be bad if this was taken too far, and something was written in a language only one person knows, but that problem already exists with the technical knowledge if something only has one mantainer.