Create a step-by-step guide for integrating MongoDB with Node.js, tailored for [BEGINNER/INTERMEDIATE/ADVANCED] developers. Cover the following: 1) Setting up a MongoDB [LOCAL/ATLAS] instance, 2) Connecting to MongoDB using [MONGOOSE/NATIVE DRIVER], and 3) Performing CRUD operations with [EXAMPLE DATA MODEL]. Include best practices for error handling, performance optimization, and security considerations like [ENVIRONMENT VARIABLES/SCHEMA VALIDATION]. Provide code snippets and explain key concepts such as [INDEXING/TRANSACTIONS] where relevant. End with a troubleshooting section for common issues like [CONNECTION TIMEOUTS/SCHEMA MISMATCHES].