Hello, GoHome. First of all, I sincerely thank you for taking the 'Building a Node.js Server Engine' course and leaving your honest review. After reviewing the rating and valuable feedback you provided, I feel a heavy sense of responsibility and sincerely apologize that we were unable to provide a sufficiently satisfying course experience that met your expectations. Since the process of learning framework design through cloning Express.js covers such in-depth content, I'm concerned that there may have been parts where the explanations were insufficient or difficult to understand during your learning process. If there were any concepts that were hard to understand or aspects of the course structure that were disappointing, please feel free to share them with me anytime. The specific feedback you provide is the greatest foundation for me to improve the course and create better content. I will diligently update the insufficient parts and do my best to return with better content in the future. Even the smallest questions that arise during your learning are welcome. If you share them through the Q&A board or open chat room, I will answer them sincerely and stay with you until the end to provide practical help for your learning. Once again, thank you for taking your valuable time to share your feedback, and I will show you continued improvement. Thank you.