package MyApp::Frontend;

use Module::Classloader;
our $C = Module::Classloader->new(namespace => 'MyApp::Adaptor');

sub get_report {
    $C->class('Report')->get_report($report_id);
}

package MyApp::Adaptor::Report;

use Module::Classloader;
our $C = Module::Classloader->new(namespace => 'MyApp::Backend');

sub get_report {
    # some business logic such as check if report exist, etc. 
    $C->class('Report')->get_report(...);
}