You need to add a new column to the sales_shipment and the sales_shipment_grid tables. Other than utilizing the default addColumn methods, what way is automatic?

A merchant requires the ability to configure contact information for their brick and mortar stores as a CSV file upload. The module already exists and contains an etc/adminhtml/system.xml file where the new field can be added.
How do you specify the class that will process the uploaded file?

In a custom module you are adding a new field to the store configuration. The field will set the value for the configuration path mycompany/mymodule/myoption.
How do you supply the default value for that configuration option?

You want to remove a column introduced by a third-party extension via declarative schema.
How do you do that?

How do you set the custom block MyCompany\MyModule\Block\A as a child for the block named product.info using layout XML?