Improbable has announced SpatialOS Open Beta and is also launching the SpatialOS Games Innovation Program in partnership with Google Cloud. SpatialOS is a cloud-based computation platform which allows for processing of millions of persistent entities. It is currently integrated with Unity but Unreal support was just announced as well. 

 Improbable is a London-based startup that recently opened an office in San Francisco. With this new strategic location, an open beta and the subsidized development program it announced, it is clear that Improbable wants people using its technology to demonstrate the power of their platform. 

Source: https://improbable.io/2017/02/27/improbable-announces-spatialos-open-beta-unreal-engine-integration-and-launches-spatialos-games-innovation-program
Learn more about SpatialOS here: https://spatialos.improbable.io/

Amazon GameLift, a server setup service for session-based games (say that quickly 10 times) can now be used with popular and custom game engines. 

Source: https://aws.amazon.com/about-aws/whats-new/2017/02/amazon-gamelift-supports-unity-unreal-engine-and-custom-c-sharp-and-c-plus-plus-engines/

Learn more about integration here: http://docs.aws.amazon.com/gamelift/latest/developerguide/integration-intro.html
Learn more about Amazon GameLift here: https://aws.amazon.com/gamelift/