I don't know if the community will consider this example to be microservices as currently defined, but many years ago I wrote client-server systems using a PC-based fat client application, and transactions running on a CICS server. I think this was pretty similar to what people currently think of as a microservices architecture, although we didn't have to worry about running/monitoring multiple servers (all the transactions/services ran on a single mainframe server), and the transaction monitor managed things like start-up and shutdown pretty simply. This approach worked really well for us, and we built several robust, scalable applications using this approach. To be clear, we numbered our users in hundreds, not thousands or millions. I can well understand how scaling this approach across many servers could be very challenging.