Distributed Transactions for MongoDB are now available in beta, extending multi-document ACID guarantees from replica sets to sharded clusters. They have a similar syntax to existing transactions and enforce snapshot isolation, making them familiar to anyone with prior transaction experience. The new feature will be shipped with MongoDB 4.2 later this year and includes support for large transactions, rich diagnostics, improved error handling, and mutable shard key values. The beta program is now open, inviting developers to sign up and take the new feature for a spin, with further instructions and best practices provided as part of participation.