I am used to, and instinctively want to, deploy microservices individually. To understand the dependencies/contracts between them and roll-out updates in such a way as I can monitor the success of individual changes, one at a time.
However, I see a number of teams that seem to treat a set of closely related microservices like a monolith - pushing out 5/6 new applications in parallel as a known and tested single unit.
Susan Fowler writes in her book Production-Ready Microservices a checklist of production-readiness characteristics. One is...
"Are deployments to production done all at the same time, or incrementally rolled out?"
When I first read this I assumed she agreed with me, that incremental was preferable. But I can see how it could be read both ways?
What did Susan Fowler mean when she wrote this, and what are the advantages of either methodology?