Note: The job is a remote job and is open to candidates in USA. Harnham is a consumer technology company with hundreds of millions of users, seeking a Senior Machine Learning Engineer to join their Ad Tech team. The role focuses on improving production machine learning systems that influence revenue and user engagement, with responsibilities including model improvement, data analysis, and collaboration with product and engineering teams.

Responsibilities

• Own and improve production machine learning models
• Analyze large-scale datasets containing millions of rows
• Improve prediction, ranking, recommendation, and optimization systems
• Design and evaluate new features that improve model performance
• Run experiments and measure business impact
• Retrain and evolve models as user behavior changes
• Translate insights from data into production code improvements
• Partner closely with Product and Engineering teams to drive revenue outcomes

Skills

• 5+ years of Machine Learning Engineering, Applied ML, or Data Science experience
• Strong Python engineering skills with daily hands-on development
• Strong SQL skills including complex multi-table joins and large-scale analysis
• Experience working with datasets containing millions of rows
• Experience building, deploying, and improving production ML models
• Strong feature engineering experience
• Proven ability to improve ML systems and drive measurable business impact
• Strong ownership and ability to operate independently
• Ad Tech optimization
• Ad ranking or bidding systems
• Recommendation engines
• Personalization systems
• Search and ranking algorithms
• Marketplace optimization
• User value optimization
• AWS, Snowflake, or online feature stores

Benefits

• Annual bonus opportunity
• Unlimited PTO
• Medical, dental, and vision coverage
• 401(k)

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