You can use Mandango in a normal way.
You can access to the mandango in the container:
$mandango = $container->get('mandango');
The mandango is initialized also automatically (in a lazy way) if you use some functionality in the documents that require it:
// creating
$article = $mandango->create('Model\Article');
$article->setTitle($title);
$article->save();
// quering
$articles = $mandango->getRepository('Model\Article')->createQuery();
// ...