Staff Machine Learning Engineer, Ads Foundational Representations

Overview

As Senior ML Engineer in the AFR team, you drive end-to-end ML projects to improve ad relevance and content understanding through embeddings and advanced models. You collaborate with cross-functional teams to define requirements, implement features, and run experiments that impact targeting, ranking, and business insights. You will work with multimodal data, large models, and knowledge graphs to enhance Reddit’s advertiser-facing products. This role offers the chance to shape state-of-the-art embeddings at scale in a data-driven, innovative environment.

Pay / Benefits

• Global Benefit programs
• Family Planning Support
• Gender-Affirming Care
• Mental Health & Coaching Benefits
• Group Personal Pension Scheme with Employer match
• Private Medical and Dental Scheme

Responsibilities

• Develop and iterate embedding models for advertising use cases (e.g., two-tower architectures, sequence models)
• Work with local and external LLMs/VLMs to extract representations, evaluate, and fine-tune models
• Build data processing and inference pipelines for developed models
• Qualitatively and quantitatively evaluate features, perform end-to-end experiments
• Ensure ML systems reliability, scalability, and performance with tests and monitoring
• Participate in modeling and coding reviews to maintain quality and standards
• Collaborate with cross-functional teams to translate business requirements into technical solutions

Key requirements

• 5+ years of hands-on experience with full lifecycle of designing, training, evaluating, testing, and deploying industry-level models
• Experience building NLP or CV models and integrating them at scale
• Experience developing complex features/embeddings for downstream models
• Experience with PyTorch or TensorFlow
• Excitement about working with data and going beyond metric numbers

• collaboration with cross-functional teams
• mentoring or tech leadership experience
• data-driven decision making
• PyTorch
• TensorFlow
• NLP models

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