Despite the rise of OpenTelemetry and eBPF, most developers don’t know what automatic instrumentation actually does under the hood. This post breaks it down—not to suggest you build your own, but to help you understand what’s going on when your tools magically “just work.” We’ll explore five key techniques that power automatic instrumentation: monkey patching, bytecode instrumentation, compile-time instrumentation, eBPF, and language runtime APIs. Each technique leverages the uniq...
