Node.js architecture can lead to critical errors like uncaughtExceptions and unhandledPromiseRejections.
Uncaught exceptions occur when errors are thrown but not caught, and unhandled promise rejections happen when promises are not caught with a .catch().
Ignoring these errors can lead to process termination without cleanup, affecting data integrity, causing resource leaks, silent failures, and security risks.
Best practices include handling fatal errors by logging full context, reporting to error-tracking services, gracefully shutting down, and converting unhandled rejections into exceptions.