[x3al]

You can replace 'microservice' with 'class, but completely asynchronous and any interaction with it can fail without caller knowing if it succeed or failed at all'.

[imtringued]

Yes, that type of class is known as "actor".

[cfontes]

As someone with a little experience troubleshooting actor based systems, having 1600 of them sounds (actors not instances) like a nightmare.