Senior Machine Learning Engineer, LS Embeddings

Design and implement scalable, high-performance machine learning models using Graph Neural Networks (GNNs), transformers, and knowledge graph approaches. Develop and optimize large-scale embedding generation pipelines for Reddit’s recommendation systems. Collaborate with ML infrastructure teams to enable efficient distributed training (multi-GPU, model/data parallelism) and low-latency serving. Work closely with cross-functional teams (Ads, Feed Ranking, Content Understanding) to integrate embeddings into various personalization and ranking systems. Drive feature engineering efforts, identifying and curating expressive raw data to enhance model effectiveness. Monitor, evaluate, and improve model performance using A/B testing, offline metrics, and real-time feedback loops. Stay up-to-date with the latest research in GNNs, transformers, and representation learning, bringing new ideas into production. Participate in code reviews, mentor junior engineers, and contribute to technical decision-making.