Apache Kafka® is known for its scalability, reliability, and performance, but understanding how it works and identifying performance bottlenecks can be challenging. In this talk, we will explore the use of flamegraphs as a tool for understanding the internals of Apache Kafka and for identifying performance issues. Flamegraphs are a visualization technique that allows you to see the relative usage of CPU and memory by different functions in a program. They provide a clear and concise view of the call stack, making it easier to understand how different components of the system are interacting and where the hot spots are. We will cover the basics of how to generate and interpret flamegraphs, and we will walk through a number of real-world examples of using them to troubleshoot performance issues in Apache Kafka® . These examples will include cases where flamegraphs helped to identify issues such as CPU and memory contention, inefficient code paths, and suboptimal configuration choices. By the end of this talk, you will have a better understanding of how to use flamegraphs to understand the inner workings of Apache Kafka® and to identify performance bottlenecks. You will also have a set of practical tips and techniques for using flamegraphs to troubleshoot performance issues in your own Kafka deployments.