Model Trainer - Focuses on optimizing the model's performance through training and validation, without direct involvement in defining business objectives.

Data Scientist - Primarily involved in data analysis and model building, but may not always have the authority or context to define business success criteria.

Machine Learning Engineer - Specializes in the technical deployment and scaling of machine learning models, with limited focus on business problem definition.

Professional Machine Learning Engineer - Bridges the gap between business and technology by defining how the model output should be utilized to solve the business problem, including setting the success criteria.