**Problem** Some companies still use the vanilla JS approach while having `{{key_name...}}` keys in their code. Then text observer is used to search for such strings and replaces them with the localized values. However, we don't have this approach properly documented. **Solution** 1. Document basics of this approach 2. Document the string format (parameters, default value) 3. Document preparing for production for this approach 4. Record simple video about this concept