This article is a free translation of the Russian one that is a transcript of the Russian video lecture done by Roman Elizarov at the Application Developer Days 2011 conference. The lecturer talked about profiling of Java applications without any standalone tools. Instead, it's suggested to use internal JVM features (i.e. threaddumps, java agents, bytecode manipulation) to implement profiling quickly and efficiently. Moreover, it can be applied on Production environments with minimal overhead. This concept is called DIY or "Do It Yourself". Below the lecture's text and slides begin. Today I'm giving a lecture "Do It Yourself Java Profiling". It's based on the real life experience that was gained during more than 10 years of developing high-loaded finance applications that work with huge amounts of data, millions currency rate changes per second and thousands of online users. As a result, we have to deal with profiling. Application pro