Live resharding is a feature introduced in MongoDB 5.0 that allows users to change the shard key for their collection on demand without any database downtime or complex data migrations. This feature eliminates the need for manual and complex resharding processes, making it easier for developers to scale out their applications horizontally while maintaining data locality and enforcing regulatory compliance. With live resharding, users can review their sharding strategy, change between range, hash, and zones, and even rehome documents to different geographic regions or age data out to slower storage tiers. The process is automated, resilient, and non-disruptive to the application, allowing developers to evolve with their apps in simplicity and resilience. Users should ensure they have sufficient storage capacity available, monitor the resharding progress, and block writes early if necessary to force completion of the resharding operation. Live resharding is available in MongoDB's fully managed Atlas data platform, Enterprise Advanced, and Community Edition, providing a huge step forward in the state of distributed systems and paving the way for future improvements in sharding flexibility and automation.