Staff ML Engineer, Ads Retrieval & Relevance

Aimlroles; Northern (KY); Hybrid; USD 230,000 - 322,000; Full time

Benefits offered by this job

Remote work

Healthcare

401k

Global benefits

Family planning

Gender-affirming care

Mental health & coaching

Flexible vacation

Parental leave

Job summary

Reddit is seeking a Staff Machine Learning Engineer to lead the Retrieval ML team. You will steer the design and evolution of retrieval models, work across data design, objectives, and production deployment, and mentor engineers on end-to-end product impact.

This role emphasizes staying close to technical details—from data design to model evaluation and experiments—while setting direction for colleagues and partnering with ads, ranking, and product teams.

Qualifications

• 7+ years of industry experience shipping applied ML products.
• Deep experience with information retrieval, candidate generation, recommender systems, ranking, or related relevancy problems.
• Strong command of retrieval modeling concepts including DNNs, embeddings, two-tower/dual-encoder models, and ANN search.
• Experience training, evaluating, debugging, and deploying deep learning models with TensorFlow, PyTorch, or similar frameworks.
• Demonstrated ownership of ML projects from problem framing to production launch and iteration.
• Strong ability to design experiments and relate offline metrics to business/user outcomes.
• Experience with large-scale behavioral/contextual datasets and complex feature pipelines.
• Excellent written and verbal communication, able to explain modeling choices to technical and non-technical audiences.

Responsibilities

• Define the technical direction and multi-year roadmap for ads retrieval modeling with stakeholders.
• Design, develop, and launch candidate-generation and retrieval models for campaigns and ads.
• Apply modern approaches such as two-tower architectures and embeddings to create product value.
• Improve retrieval stack including labels, sampling, hard-negative mining, and embedding generation.
• Work with ANN and vector retrieval systems, balancing recall, relevance, latency, and cost.
• Establish evaluation practices linking retrieval metrics to ads and user outcomes.
• Lead offline analysis and online experiments, translating results into next iterations.
• Collaborate with ranking, ads platform, auction, and product teams to integrate retrieval models.
• Write design docs, review code/model changes, and raise quality standards.
• Mentor ML engineers and grow team expertise in retrieval and representation learning.

Skills

Information retrieval

Candidate generation

Recommender systems

Two-tower models

Embeddings

Nearest-neighbor search

Production-grade code

Mentoring

Communication

Tools

TensorFlow

PyTorch

Job description

Reddit is seeking a Staff Machine Learning Engineer to lead the Retrieval ML team. You will steer the design and evolution of retrieval models, work across data design, objectives, and production deployment, and mentor engineers on end-to-end product impact.

This role emphasizes staying close to technical details—from data design to model evaluation and experiments—while setting direction for colleagues and partnering with ads, ranking, and product teams.