In MongoDB 4.2, pipeline-powered updates are now available, bringing significant improvements to update commands and aggregation pipelines. The update command can now use aggregation pipelines, allowing for more powerful transformations of documents without round-tripping data to the client. This enhancement brings pipeline power to the update command, enabling conditional statements and calculations, such as trigonometry, regular expressions, and conversions between degrees and radians, directly on the server. Additionally, new operators have been added to the aggregation framework, including $set for adding fields, $unset for removing fields, and $replaceWith for replacing entire documents. These changes aim to unify the language used in queries and aggregations, providing more expressive queries and pipeline operations. The introduction of $$NOW also allows for injecting timestamps into documents without round-tripping data to the client. With MongoDB 4.2, developers can now work with a more powerful and flexible aggregation framework, enabling complex string parsing and calculations directly within updates and aggregations.