A merchant gives you the module MyCompany_MyModule to install.
How do you identify which REST endpoints are supported by the module?

A module you are working on needs to send a newsletter to all subscribed customers at predefined intervals.
Which two actions do you take to make sure the newsletter is sent? (Choose two.)

You are facing a bug, which is supposedly caused by the customization of
\Magento\Catalog\Api\ProductRepositoryInterface::save().
To resolve the issue, you decide to find all logic which customizes this method. Which two places do you search for customization declarations? (Choose 2)

You are implementing a custom module MyModule, which provides an implementation of
\Psr\Log\LoggerInterface called \MyCompany\MyModule\Logger.
The LoggerInterface has the default preference declared in app/etc/di.xml.
Keeping upgradability in mind, how do you make \MyCompany\MyModule\Logger the default implementation of the LoggerInterface globally?

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?