Filtering Documents using Expressions in MongoDB Collections ($expr, $size, $in, $and, etc)

In this lesson, we learn that we can perform advanced filtering in MongoDB by using expressions within our queries. All thanks to $expr.

We demonstrate how to compare multiple document properties, such as ensuring age is less than salary using comparison operators ($lt, $lte, $gt, $in, $nin, etc).

Additionally, we explore filtering based on the length of an array ($size) to check for specific skills.