Is there a way to have Backblaze exclude .svn folders?

The current GUI only allows the exclusion of individual folders, not all folders called e.g. .svn

But there is an advanced way of adding exclusions - see

https://help.backblaze.com/hc/en-us/articles/220973007-Advanced-Topic-Setting-Custom-Exclusions-via-XML

As an example, I added the following rule to exclude .git hidden folders, only if they were in my ~/Sites folder (another similar could apply to .svn, node_modules etc.):

<excludefname_rule plat="mac" osVers="*"  ruleIsOptional="t" skipFirstCharThenStartsWith="users/" contains_1="/sites/" contains_2="/.git/" doesNotContain="*" endsWith="*" hasFileExtension="*" />

You can change which folders and files are excluded from the backup, by clicking on the Settings… button on the Backblaze Control Panel and selecting the Exclusions tab.