gitlab-org--gitlab-foss/app/finders/README.md

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.execute(project, user, filter)

It will help keep models thiner.