Staff ML Engineer, Retrieval — Remote & High-Impact

Remote; San Francisco (CA); Remote; USD 260,000 - 340,000; Full time

Benefits offered by this job

100% remote

Healthcare benefits

401k with employer match

Global benefits programs

Parental leave

Mental health support

Flexible vacation

Job summary

Reddit is hiring a Staff Machine Learning Engineer to lead the Retrieval ML team. You will design and evolve retrieval models that improve relevance, advertiser outcomes, and user experience at Reddit scale.

You’ll stay close to data, objectives, modeling, evaluation, experimentation, and launch while guiding other engineers. You will mentor engineers, set the technical direction for candidate generation and retrieval across campaigns and ads, and partner with ranking and measurement teams to

Qualifications

• 7+ years of industry experience with applied ML products.
• Deep experience with information retrieval and recommender systems.
• Strong understanding of retrieval modeling concepts (DNNs, embeddings, two-tower).
• Experience training and deploying deep learning models with TensorFlow or PyTorch.
• Ownership of ML projects from problem framing to production.

Responsibilities

• Define multi-year roadmap for ads retrieval modeling.
• Design, develop, and launch candidate-generation and retrieval models for campaigns.
• Apply advanced retrieval techniques (two-tower, embeddings, graph-based methods).
• Improve retrieval stack decisions: objectives, sampling, hard negatives, features, embeddings.
• Work with ANN and vector retrieval systems focusing on recall, relevance, latency, and cost.
• Establish evaluation practices linking retrieval metrics to business outcomes.
• Lead offline analyses and online experiments, translating results to iterations.
• Collaborate with ranking, ads platform, and measurement teams for integration.
• Write design docs, review code, and raise quality standards.
• Mentor ML engineers and grow retrieval/recommendation expertise.

Skills

7+ years exp

Info retrieval

Retrieval modeling

Two-tower models

DL frameworks

Experiment design

Large-scale data

Engineering fundamentals

Technical leadership

Communication skills

Tools

TensorFlow

PyTorch

Job description

Reddit is hiring a Staff Machine Learning Engineer to lead the Retrieval ML team. You will design and evolve retrieval models that improve relevance, advertiser outcomes, and user experience at Reddit scale.

You’ll stay close to data, objectives, modeling, evaluation, experimentation, and launch while guiding other engineers. You will mentor engineers, set the technical direction for candidate generation and retrieval across campaigns and ads, and partner with ranking and measurement teams to