Python Machine Learning Specialist

About OpenTrain

OpenTrain is the #1 platform for finding and building careers in AI training and data labeling. The platform helps contributors discover projects, build a unified portfolio, and grow sustainable freelance careers training AI systems.

OpenTrain emphasizes flexible, remote work that makes it easy to apply, track experience, and show the real-world model-training contributions that matter to employers.

• Free to join and builds a single portfolio of AI training work.
• Focused on remote, flexible roles that fit part-time schedules.
• Connects contributors to diverse ML and data-labeling projects.

About AI training work

AI training (data labeling and human-in-the-loop model work) is the human side of building modern AI systems. Contributors prepare, evaluate, and refine the examples models learn from, shaping how models behave in deployment.

These roles range from annotation to engineering: you’ll work directly on model design, evaluation, and operationalization to improve accuracy, reliability, and real-world performance.

• Work is 100% remote and often flexible by design.
• Many roles require only domain fluency and attention to detail; this one asks for ML engineering experience.
• Contributors affect state-of-the-art AI behavior through hands-on experiments and documentation.

The role

OpenTrain is recruiting for a Python Machine Learning Specialist (contractor) to help train next-generation AI systems through high-quality, real-world input. This is a part-time, remote contractor role requiring 20+ hours per week.

You will design, refine, and evaluate ML models, manage training data in MongoDB, implement preprocessing and training pipelines, and document experiments for reproducibility.

• Employment type: Contractor, Part-time.
• Time commitment: 20+ hours/week.
• Location: Remote, worldwide; English required.

What you'll do

You’ll lead model development tasks, collaborate with cross-functional contributors, and deliver documented, repeatable ML workflows that support training and inference.

• Design, develop, and refine ML models using Python and relevant libraries.
• Manage and query training/validation data using MongoDB.
• Conduct model evaluation, tune hyperparameters, and benchmark results.
• Integrate preprocessing and data pipelines to support training and inference.
• Document methodologies, experiments, and outcomes for transparency.
• Deliver actionable insights and recommendations from ML findings.

Requirements

Candidates must demonstrate hands-on ML experience and strong Python skills. The role expects familiarity with common ML frameworks, data management, and operationalization of models.

• Demonstrated expertise with Python.
• Familiarity with scikit-learn, TensorFlow, or PyTorch.
• Hands-on experience with MongoDB for data manipulation and retrieval.
• Understanding of model evaluation metrics, feature engineering, and preprocessing.
• Experience deploying or operationalizing ML models in cloud or enterprise environments.
• Strong problem-solving skills and clear written documentation/communication.

Who should apply

This role fits intermediate ML engineers or data scientists who want flexible, impactful contractor work contributing to model training pipelines. If you have delivered ML solutions in real-world settings and enjoy documenting reproducible experiments, apply.

You should be comfortable adapting to evolving project needs, collaborating remotely, and working with text-based datasets and evaluation tasks.

• Experience level: Intermediate.
• Preferred background: ML engineers, data scientists, applied researchers.
• Work involves text data and evaluation/rating tasks as part of model training.

Compensation, data, and how it works

Pay is hourly in USD; the role lists an hourly range of $40–$100/hr. OpenTrain engages contractors for focused ML training and evaluation work and will share project-specific onboarding and tooling details during hiring.

This project uses text data (dataType: TEXT) and label types include computer programming/coding and evaluation/rating. The labeling software is listed as OTHER; specific platform or tooling will be provided by the client during onboarding.

• Pay type: Hourly (PAY_PER_HOUR), USD $40–$100/hr.
• Data type: TEXT; Label types: COMPUTER_PROGRAMMING_CODING, EVALUATION_RATING.
• ; specific tools and access provided on project start.