How to Get Complex Data with Aggregation Pipeline in MongoDB

Explore the power of MongoDB's Aggregation Pipeline for complex data retrieval and transformation. Learn how to construct multi-stage pipelines to filter, join, and reshape data effectively. Begin with matching records based on specific criteria, then use lookups to gather related information from other collections. Master the use of local and foreign fields for accurate data retrieval, focusing on counting and organizing subscriber data for user profiles. Discover how to customize output using addFields, ensuring final results meet project requirements. Conclude with practical examples of building controller functions to fetch user profiles and watch history, demonstrating how the aggregation pipeline enhances efficient data management in MongoDB.