Thanks to the exception stack I examined, I understood that I had a model registry issue. I had used joblib to save the model file on my system, and I believed that the model registration in ClearML storage was automatic. So when I made the API call, the model path returned NoneType. Once I fixed that, I was able to serve my model and make API calls giving prediction results. Also, thanks to your help, I understood that I needed custom serving, and I was able to modify the preprocess.py file to suit my problem. Once again, thank you very much for your help. I was able to test ClearML serving, and I greatly appreciated its simplicity and scalability. I believe it's a tool I'll adopt in my work. The next step for me is to test ClearML's monitoring features.