"projects": {
  $userId: {
    $auto_generated_project_id_1: {
      name: 'first_project',
      ...
    },
    $auto_generated_project_id_2: {
      name: 'first_project',
      ...
    },
  }
}

"folders": {
  $userId: {
    $auto_generated_folder_id_1: {
      name: 'first_project',
      parentId: 'parentId to go back',
      ...
    },
    $auto_generated_folder_id_1: {
      name: 'first_project',
      parentId: 'parentId to go back',
      ...
    },
  }
}

"projects": {
  $userId: {
    $auto_generated_project_id_1: {
      'name': 'first_project',
      'folderId': 'id_of_folder'
      ...
    },
    $auto_generated_project_id_2: {
      'name': 'first_project',
      'folderId': 'id_of_folder'
      ...
    },
  }
}

"folders": {
  $userId: {
    'depth_0': {
      $auto_generated_folder_id_1: {
        name: 'first_project',
        parentId: '',
        projectIds: [] // not all sub projectIds, only first level children
        ...
      },
      $auto_generated_folder_id_1: {
        name: 'first_project',
        parentId: '',
        projectIds: [] // // not all sub projectIds, only first level children
        ...
      },
    },
    'depth_1': {
      $auto_generated_folder_id_1: {
        name: 'first_project',
        parentId: 'id_amongst_depth_0',
        projectIds: [] // not all sub projectIds, only first level children
        ...
      },
      $auto_generated_folder_id_1: {
        name: 'first_project',
        parentId: 'id_amongst_depth_0',
        projectIds: [] // not all sub projectIds, only first level children
        ...
      },
    },
    'depth_2': {
      $auto_generated_folder_id_1: {
        name: 'first_project',
        parentId: 'id_amongst_depth_1',
        projectIds: [] // not all sub projectIds, only first level children
        ...
      },
      $auto_generated_folder_id_1: {
        name: 'first_project',
        parentId: 'id_amongst_depth_0',
        projectIds: [] // not all sub projectIds, only first level children
        ...
      },
    },
    ...
  }
}

"projects": {
  $userId: {
    $auto_generated_project_id_1: {
      'name': 'first_project',
      'folderId': 'id_of_folder'
      ...
    },
    $auto_generated_project_id_2: {
      'name': 'first_project',
      'folderId': 'id_of_folder'
      ...
    },
  }
}