How should I structure AL event subscribers?

Question

Where should event subscribers live in an AL extension when multiple features need independent handlers? I want the structure to remain testable and easy to discover.

[EventSubscriber(ObjectType::Codeunit, Codeunit::"Sales-Post", 'OnAfterPostSalesDoc', '', false, false)]
local procedure HandlePostedDocument()
begin
    // feature behavior
end;

Group subscribers by business responsibility rather than putting every event in one global codeunit. Keep handlers small and delegate complex work to testable services.

Create feature-oriented subscriber codeunits, use meaningful names, avoid state, and move reusable logic behind focused procedures or interfaces. This keeps permissions, tests and ownership clearer.

Also document why each subscriber exists and include automated tests for filters, order-sensitive behavior and failure paths.