Machine Learning Engineer Expert at Mercor

Machine Learning Engineer Expert | $90/hr | Worldwide Remote

Mercor is seeking experienced Machine Learning Engineers and Applied ML Researchers to design, solve, and evaluate complex machine learning challenges that reflect real-world ML workflows. This is a high-impact contractor role requiring deep hands-on modeling expertise and familiarity with modern ML techniques across diverse domains and data modalities.

What You'll Do

• Develop end-to-end machine learning solutions for challenging prediction and modeling problems
• Analyze datasets and define appropriate modeling approaches, validation strategies, and evaluation metrics
• Perform exploratory data analysis, feature engineering, and data preprocessing
• Train, tune, and evaluate ML models across tabular, text, image, and time-series datasets
• Build strong reference solutions using industry-standard techniques and best practices
• Review and validate the technical quality of machine learning projects and deliverables
• Document methodologies, assumptions, and evaluation results in a clear, reproducible manner
• Identify opportunities to improve model performance through systematic experimentation

Required Qualifications

• Master's degree or PhD in Computer Science, Machine Learning, Statistics, Mathematics, Electrical Engineering, or a related field from a top-tier university
• 2+ years of hands-on experience developing, training, evaluating, and optimizing ML models in a professional or research setting
• Strong proficiency in Python and modern ML frameworks such as scikit-learn, XGBoost, LightGBM, PyTorch, or TensorFlow
• Demonstrated experience building end-to-end ML solutions including data preparation, model development, validation, and evaluation
• Strong understanding of model evaluation metrics, validation methodologies, and experimental design
• Experience in one or more of: tabular ML, NLP, computer vision, recommendation systems, ranking systems, or time-series forecasting
• Ability to work independently on open-ended ML problems and deliver high-quality technical outputs

Preferred Qualifications

• PhD from a leading research university
• Experience at top technology companies, AI labs, research institutions, or high-growth startups
• Participation in competitive ML or data science competitions
• Familiarity with advanced techniques such as ensembling, hyperparameter optimization, transfer learning, foundation model fine-tuning, or reinforcement learning
• Publications, patents, or significant open-source contributions in ML or AI
• Experience reviewing, mentoring, or evaluating the work of other ML practitioners