ALT Layered diagram titled "Tempest + Ecotone — how the integration works": bottom layer, application level, Tempest (container, discovery, database models, HTTP, views, authentication) installed with composer require tempest/framework; middle layer, architecture level, Ecotone (durable messaging, asynchronous processing, failure recoverability, event sourcing, workflow engine) installed with composer require ecotone/tempest; top layer, business logic — aggregates, command/event/query handlers, projections, workflows as plain PHP classes with attributes — labelled "this is what you write"