Staff Machine Learning Engineer (Ads Foundational Representations)

Quick Facts

• Role: Staff Machine Learning Engineer (Ads Foundational Representations)

• Focus: Building embeddings and representations for Reddit Ads signals, relevance, targeting, and business insights

Description

Lead the technical direction for multiple pillars that build embeddings and relevance signals for Reddit Ads, covering multimodal/content embeddings, contextual and behavioral relevance, knowledge graph embeddings, user intent modeling, and LLM-based representations. Own end-to-end ML work from business gap analysis through engineering execution, evaluation, and experimentation across offline and online settings. Approximately 50% of your time is technical leadership and mentorship, with the remaining 50% spent on hands-on data analysis, modeling, and automation.

Responsibilities

• Provide technical leadership and mentorship to MLEs; drive design reviews and establish best practices for analysis, modeling, and engineering

• Work with team/org leadership to develop technical strategy for content-based embeddings and ad relevance

• Develop new or iterate on embedding models for advertising use cases (e.g., aggregation pipelines, two-tower architectures, sequence models)

• Use local and third-party LLMs/VLMs to extract representations; develop evaluation methodologies; prompt tune and fine-tune large models

• Build data processing and inference pipelines for developed models

• Conduct qualitative and quantitative evaluation; run end-to-end experimentation from internal benchmarks to recommender offline metrics and online experiments

• Ensure reliability, scalability, and performance via automated tests, monitoring, and model management best practices

• Participate in modeling and coding reviews and provide feedback to meet quality and performance standards

• Collaborate cross-functionally to translate business requirements into technical solutions

Requirements

• 7+ years of hands-on experience designing, training, evaluating, testing, and deploying production ML models

• Demonstrated Staff-level technical leadership (mentoring, raising standards, leading complex cross-functional ML projects from requirements and design through execution)

• Excellent communication skills in writing and in presentations across different audiences

• Strong track record working on large-scale content-rich NLP/CV problems using embeddings

• Established data-driven approach for ML system development and willingness to investigate metrics

• Familiarity with the Ads domain and/or Search/Recommender systems

• Experience with PyTorch or TensorFlow

Benefits

• Comprehensive healthcare benefits and income replacement programs

• 401k with employer match

• Global benefits for lifestyle and professional development (including workspace support and caregiving support)

• Family planning support and gender-affirming care

• Mental health and coaching benefits

• Flexible vacation and paid volunteer time off

• Generous paid parental leave

• Pay transparency: base salary range $230,000–$322,000 USD; equity in the form of RSUs may apply