OpenTrain AI is seeking a Mechanical Engineering AI Training Expert to evaluate AI-generated engineering solutions, identify technical errors, check reasoning quality, and draft model explanations. Applicants must hold at least a bachelor's degree in Mechanical Engineering, Aerospace Engineering, or Engineering Physics, possess C1 English proficiency, and commit to 20+ hours per week. The role is open to remote candidates across 17 specified countries including the United States, Germany, Brazil, and India.