Running stress- or load-tests of asynchronous REST/HTTP services with JMeter is only the first step in performance improvement. If the applications have problems when load increases, you need to find where the issues are. You can spend a lot of time to examine the code base before – if ever – finding the cause of the performance problem. This blog post provides an introduction on how to record and examine telemetry performance measurements with Yourkit3 after running JMeter tests.