Unity Senior Machine Learning Engineer Ads Fraud Detection 

United States, California, San Francisco 

975348274

These models power our ad ranking and recommendation systems, helping advertisers reach the right users at the right time by accurately estimating engagement and conversion likelihood. By leveraging large-scale behavioral data, creative features, and contextual signals, we continuously improve the relevance and accuracy of our predictions. This drives key outcomes such as higher user engagement, stronger conversion performance, and better return on ad spend — enabling advertisers to achieve their goals while delivering a better experience for users.

• Design, implement, and maintain high-performance fraud detection models to identify and block fraudulent activities at the publisher, game, and user levels.
• Build and refine systems to analyze user behavior, transaction patterns, and contextual signals, enabling accurate and timely detection of suspicious or malicious activity.
• Ensure model quality and reliability by continuously monitoring performance, calibrating predictions, and addressing data drift or delayed feedback.
• Actively participate and work with other leads to set the long term direction for the team, plan and oversee engineering designs and project execution.
• Effectively communicate complex technical concepts to non-engineering stakeholders.

• Advanced degree (MS or Ph.D.) in Computer Science, Machine Learning, Statistics, related field, or equivalent practical experience.
• 5+ years of hands-on experience building and operating large-scale systems for detection, monitoring, or risk management in ads, payments, or related domains.
• 3+ years of experience designing and deploying fraud detection or anomaly detection models, user behavior modeling, or risk scoring systems.
• Significant experience in one or more general-purpose programming languages like Python, Go, Scala, C++ or similar.
• Knowledge of metric design, experimentation methodologies, and large-scale data analysis.

• Experience designing and productionizing optimization algorithms in an ad serving platform and/or other marketplaces.
• Experience with state-of-the-art control systems, reinforcement learning algorithms.

Pursuant to the San Francisco Fair Chance Ordinance, we will consider for employment qualified applicants with arrest and conviction records.

This position requires the incumbent to have a sufficient knowledge of English to have professional verbal and written exchanges in this language since the performance of the duties related to this position requires frequent and regular communication with colleagues and partners located worldwide and whose common language is English.