While an official list of customers can't be published, you can get some ideas from the speakers at the last two RabbitMQ summits - https://rabbitmqsummit.com/

Also, see the following articles:

Laika - https://www.rabbitmq.com/blog/2019/12/16/laika-gets-creative...

Bloomberg - https://tanzu.vmware.com/content/rabbitmq/keynote-growing-a-...

Goldman Sachs - https://tanzu.vmware.com/content/rabbitmq/keynote-scaling-ra...

Softonic - https://www.cloudamqp.com/blog/2019-01-18-softonic-userstory...

I recommend going through presentations of the RabbitMQ Summit. https://www.youtube.com/channel/UCp20sSF_JZv5aqpxICo-ZpQ

There are some big companies talking about their experience.

We use it heavily at Reddit as well.