Performance
This is a key requirement in choosing a programming language for a microservice. When we talk about performance for microservices, there are many points where performance can be a problem: the network communication layer, access to the database, where the servers are available. All these points can be problematic for microservices. The programming language cannot be another can of slowness.
When the target is microservice performance, no matter the skill of the development team, it should be used for best second language benchmarks and stress tests.
Something that often creates misunderstanding is considering the speed of a development team to implement a feature and performance requirement. Performance is related to a metric similar to how a code behaves when responding to a request or performing a task. Definitely, personal or team performance is not included in this metric.