Staff Machine Learning Engineer, Retrieval
Core
Lead the design and evolution of retrieval models for identifying relevant advertising candidates on Reddit's advertising surfaces.
Role type
Staff Machine Learning Engineer (Applied ML, Technical Leadership)
Builds
Candidate-generation and retrieval models for campaigns and ads across Reddit's advertising surfaces
Domain
Internet / Online Advertising / Machine Learning
Deliverable
production ML models
Required skills
Information retrieval, candidate generation, recommender systems, DNN, embeddings, two-tower models, approximate nearest-neighbor search, deep learning frameworks (TensorFlow/PyTorch), experimental design, large-scale data pipelines, software engineering fundamentals, technical leadership
Preferred skills
Ads retrieval, ad serving, recommendation, search relevance, sequential modeling (RNNs/Transformers), graph-based methods, multimodal signals
Technologies
TensorFlow, PyTorch, two-tower architectures, embeddings, vector retrieval systems
Responsibilities
Define technical direction and multi-year roadmap for ads retrieval modeling; Design, develop, and launch candidate-generation and retrieval models; Apply modern deep learning techniques to improve product value; Improve the retrieval stack including objectives, labels, sampling, and feature design; Work with approximate nearest-neighbor systems to optimize recall, latency, and cost; Establish evaluation practices connecting retrieval metrics to business outcomes; Lead offline analysis and online experiments; Partner with downstream ranking and auction teams; Mentor ML engineers
Seniority
Staff, Technical Leadership
