Microservices are great but they are also a pain to maintain. With so many moving components, microservices make it difficult to maintain and identify the bottlenecks. The mindset has to be changed and applications need to be designed for failure.
Applications are split into multiple smaller services and they should be. These small services should be interconnected. They should know where the other services live and how to connect with them. They should be consistent and highly available. The connections should be intelligent and configurable. These services should be secured, traffic between services should be encrypted, requests should be properly authorized and authenticated. Since these services scale up and down autonomously, it is important to monitor and observe them for any issues, errors, exceptions, time lag, and other things.