What about this approach:
product: {
id: 1,
name: 'Original Name',
description: 'Original Description',
price: 33,
date: '2019-03-13',
translations: {
es: {
name: 'Nombre Original',
description: 'Descripción Original',
}
}
}
If the user selects some language different to the default and the key translations exists in the object, you only need to merge it, and if any key has no translation, the original remains.
Another advantage is if you need to remove the translation feature or add/remove some language, you only need to change or remove the translation key and not having to refactor the entire schema.