The Instrumentor is a new LLVM pass that allows instrumenting code in a simple and customizable way. It can be used from within LLVM as any other pass, or from any frontend via a descriptive JSON file. The Instrumentor provides a unified and simple method for instrumenting code, reducing maintainability costs and code replication, as well as paving the path for future instrumentation-based tools. Our technical talk will cover the functionalities of the Instrumentor, which will be helpful for compiler, runtime and tool developers, and we will show its versatility through several use cases.