What is the best workflow in terms of translation review?

Have you implemented a review step in your localization process? Are your reviewers working inside Transifex? How do they pass feedback along to the translators? Who are your reviewers? Are they in country and part of your organization in different roles? Or do you have professional reviewers working on it? We encourage you to share your workflow and see how other users might benefit or add different best practices that can improve your process.