Elastic Beanstalk worker environments – AWS Elastic Beanstalk

If your AWS Elastic Beanstalk application performs operations or workflows that take a long time to complete, you can offload those tasks to a dedicated worker environment.Decoupling your web application front end from a process that performs blocking operations is a common way to ensure that your application stays responsive under load.

https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features-managing-env-tiers.html