What is monkey-patching in the context of Node.js APM (Application Performance Monitoring) tools, and what are its risks?

APM tools like New Relic or Datadog commonly instrument an application by monkey-patching -- overriding core module methods (like http.request or a database driver's query method) at runtime to inject timing and tracing logic transparently, without requiring the application code itself to change. The risk is that patched functions can subtly change behavior (altering stack traces, breaking assumptions about function.length or this binding), and multiple APM/tracing libraries patching the same method can conflict, causing hard-to-diagnose bugs.

// Simplified monkey-patch example
const originalRequest = http.request;
http.request = function(...args) {
  const start = Date.now();
  const req = originalRequest.apply(this, args);
  req.on('response', () => console.log('Request took', Date.now() - start, 'ms'));
  return req;
};