Yes, Facebook is one of the many big names that have been using microservices. The present times demand for Microservices wherein we create multiple individually focused modules with well defined interfaces and then combine them together to make a scalable, testable product. The product or software which might have taken an year to deliver can now be delivered in weeks with the help of Micro Service Architecture.
Example of companies using Microservices:
There are endless examples of companies using microservices in these modern times.