In a general sense, follow SWAT deploy guidelines.
More specifically, we will endeavour to SWAT only those changes needed to enable, disable, or reconfigure a feature. However, sometimes there'll be the need to SWAT a fix for a critical bug. The criticality of bugs will be assessed case-by-case by at least the Tech lead but the following should make it easy for anyone to assess.
Criticality
editA critical bug is one that meets the SWAT deploy guidelines and causes either a stable feature or one or more wikis to become unresponsive or unusable. If the feature is in beta or alpha, then we likely won't consider the bug critical.
A design change should be SWAT deployed if it falls under any of the following categories:
Visual issue If the visual regression or a fix interferes with the function or a workflow of a feature it can be considered critical
Exception note: if the visual issue occurs on the most frequently viewed parts of our software e.g. Top of the wikipedia article namespace. It can also be considered as a critical fix.
Functional issue If the bug in software prohibits a user from either exiting or moving forward in the system, it can be considered as a critical fix
When in doubt Ping nzr, rho, or pginer on #wikimedia-design for support
What happens if the bug isn't considered critical?
editWe will endeavor to fix it in a timely manner and let the fix roll out as part of the weekly deployment cycle.