The blog post delves into the new auto instrumentation capabilities of the Elastic APM .NET Agent, which utilizes a profiler-based approach to instrument and trace .NET applications without requiring code changes or recompilation. This method leverages the CLR Profiling APIs to rewrite methods of interest at runtime, enabling the Elastic APM agent to track operations that were previously challenging to monitor, such as Kafka's produce and consume operations and various ADO.NET provider interactions. The auto instrumentation is currently in its first public beta and supports several technologies, with plans to expand further. The post also highlights the potential of using Rust for writing CLR profilers, offering memory safety benefits and interoperability with C and C++. It further explains how method instructions are rewritten for APM purposes, detailing the considerations involved in this process. Users are encouraged to try the beta and provide feedback, with the anticipation that this technology will evolve to facilitate tracing without code modifications, similar to capabilities offered by the APM Java agent. The Elastic APM profiler auto instrumentation is released under the Apache 2.0 license.