DRIVERS-1967 : Evergreen scripts for serverless provisioning have been updated in mongodb-labs/drivers-evergreen-tools@577c905 . The serverless-expansion.yml file generated by create-serverless.sh now has only two relevant expansions: SERVERLESS_URI and SERVERLESS_INSTANCE_NAME : SERVERLESS_URI is the SRV URI to be used for all connections to the serverless instance. Drivers MUST still add the username and password when using this connection string. SERVERLESS_INSTANCE_NAME is used by the delete-instance.sh script. Additionally, drivers MAY define SERVERLESS_INSTANCE_NAME before calling create-instance.sh if they do not want to use a randomly generated name. Drivers MUST update the Evergreen environment variables specified in the Atlas Serverless credentials Google Doc . Drivers that have previously implemented DRIVERS-1375 will note that only the SERVERLESS_DRIVERS_GROUP variable has changed. It now points to a new Atlas project, which is configured to provision serverless instances where the load balancer is backed by a single proxy. Revised guidelines for handling useMultipleMongoses in legacy and unified test runners are discussed in mongodb/specifications@1b471f1 . To summarize, since the URI now points to a load balancer backing a single serverless proxy, useMultipleMongoses is ignored when testing against Atlas Serverless.