The document discusses different communication channels for heterogeneous environments including databases, webhooks, publish/subscribe, and RPC. It then evaluates several queue systems like ActiveMQ, RabbitMQ, and Faktory. Faktory is recommended for simple interconnections due to its easy setup costs, support for most languages, and ability to handle around 1,000 requests per second. For more requests, considerations include required speed, available resources, whether an MQ server is acceptable, and language support requirements.