Finders
This type of classes responsible for collection items based on different conditions. To prevent lookup methods in models like this:
class Project
def issues_for_user_filtered_by(user, filter)
# A lot of logic not related to project model itself
end
end
issues = project.issues_for_user_filtered_by(user, params)
Better use this:
issues = IssuesFinder.new(project, user, filter).execute
It will help keep models thiner.