Before you decide to optimize something in a microservice, you have to measure its performance. You shouldn't write optimal and fast microservices from the start, because not every microservice needs good performance, and if your microservice has bottlenecks inside, it will stumble on heavy loads.
Let's explore a pair of benchmarking tools. We will explore tools that are written in Rust, because they can be simply used to construct your own measuring tool if you need to test a special case with extremely high load.