The orchestration overhead must be huge, but it sounds like they have focused on automating the pain of that away as much as possible.

To me it looks like an Alan Kay style of OOP design. From that standpoint, replace 'microservice' with 'class' (or 'actor') and 1600 of them isn't that ridiculous.

It'd be an interesting system to browse. I'm actually curious if they've built any tooling around making the codebase easier to navigate and edit. Smalltalk handles a huge amount of tiny classes by having good browsing tools. What would you use for a Go codebase of this size?