Senior Machine Learning Engineer, Ads Targeting

Reddit is a community of communities where people can dive into anything through experiences built around their interests, hobbies, and passions. Our mission is to bring community, belonging, and empowerment to everyone in the world. Reddit users submit, vote, and comment on content, stories, and discussions about the topics they care about the most. From pets to parenting, there’s a community for everybody on Reddit and with over 50 million daily active users, it is home to the most open and authentic conversations on the internet. For more information, visit redditinc.com.

We’re evolving and continuing our mission to bring community, belonging, and empowerment to everyone in the world. Providing a delightful and relevant experience to our users applies to our Ads like all of our offerings, and we’re excited to build a product that is best-in-class for our users and advertisers. The year ahead is a busy one - join us! 

Reddit is continuing to grow our teams with the best talent. We're completely remote-friendly and will continue to be after the pandemic.

Ads Targeting ML engineers are focused on designing and implementing end-to-end ML systems and solutions for improving targeting products. Some examples of projects that the team owns:

• Improve targeting models’ quality by experimenting with in-house models or open-source options
• Create deep learning encoders to create Ads Targeting specific embeddings for contextual and behavioral entities
• Leverage large language models to create better representations for Reddit entities and content for ads targeting purposes
• Develop highly efficient retrieval ranking and models with a good balance between model performance and computation efficiency 
• Create dense retrieval solutions by leveraging the most performant approximate nearest neighbor search

As a Senior Machine Learning Engineer in the ads targeting team, you will research, formulate and execute our mission to deliver the most relevant audiences to advertisers under the right context with data and ML-driven solutions. 

Your Responsibilities:

• Build large-scale and low-latency nearest-neighbor search systems based on dense representations/embeddings
• Build custom deep learning models to learn representations for Reddit-specific entities and advertiser campaign entities 
• Systematic feature engineering works to convert all kinds of raw data in Reddit (dense & sparse, behavior & content, etc) into features with various FE technologies such as aggregation, embedding, sub-models, etc.  
• Be a mentor and cross-functional advocate for the team
• Contribute meaningfully to team strategy. We give everyone a seat at the table and encourage active participation in planning for the future.

Who You Might Be:

• Successful track record of applying machine learning techniques in addressing real-world problems
• Comfort analyzing high-volume natural language and multimodal data from varying sources
• Experience communicating complex research and ideas in a clear, precise, and actionable manner
• Experience with designing end-to-end ML systems
• Experience in content recommendations, NLP, and ads personalization
• Experience with representation learning, deep learning, and approximate nearest neighbor search
• Experience building nearest-neighbor search systems
• Experience with the Ads domain is a plus
• Some tools and technologies that are relevant: Transformers, Language Models, Spacy, Keras, Tensorflow, Pytorch, Numpy,  SageMaker, Vertex AI, FAISS, NMSLIB, ScaNN, OpenSearch, ElasticSearch, Vector Databases, Similarity Search, Graph Neural Nets, Deep Graph Library, Pytorch Geometric

Benefits:

• Comprehensive Health benefits
• 401k Matching
• Workspace benefits for your home office
• Personal & Professional development funds
• Family Planning Support
• Flexible Vacation (please use them!) & Reddit Global Days Off
• 4+ months paid Parental Leave
• Paid Volunteer time off

Pay Transparency:

This job posting may span more than one career level.

In addition to base salary, this job is eligible to receive equity in the form of restricted stock units, and depending on the position offered, it may also be eligible to receive a commission. Additionally, Reddit offers a wide range of benefits to U.S.-based employees, including medical, dental, and vision insurance, 401(k) program with employer match, generous time off for vacation, and parental leave. To learn more, please