Reddit

Staff Machine Learning Engineer, Retrieval

Reddit
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11 hours ago
Remote, United StatesStaff+
H1B sponsor

Base Salary

$230k - $322k/yr

Responsibilities

  • Define the technical direction and multi-year roadmap for ads retrieval modeling.
  • Design, develop, and launch candidate-generation and retrieval models for campaigns and ads across Reddit’s advertising surfaces.
  • Apply two-tower architectures, representation learning, embeddings, sequence models, graph-based methods, and deep learning techniques to retrieval problems.
  • Improve objectives, labels, sampling strategies, hard-negative mining, feature design, embedding generation, candidate filtering, and retrieval depth.
  • Work with approximate nearest-neighbor and vector retrieval systems while balancing recall, relevance, freshness, diversity, coverage, latency, and cost.
  • Establish evaluation practices connecting retrieval metrics to downstream advertising and user outcomes.
  • Lead offline analyses and online experiments and translate results into modeling iterations.
  • Partner with ranking, ads platform, auction, measurement, and product teams to integrate retrieval models into the ads funnel.
  • Write design documents, review code and model changes, and improve modeling, testing, observability, and production ownership.
  • Mentor ML engineers and grow team expertise in retrieval, recommendation, and representation learning.

Requirements

  • 7+ years of industry experience, including substantial experience building and shipping applied ML products.
  • Deep experience with information retrieval, candidate generation, recommender systems, ranking, or related relevance problems.
  • Strong understanding of DNNs, embeddings, two-tower or dual-encoder models, approximate nearest-neighbor search, and multi-stage retrieval.
  • Deep experience training, evaluating, debugging, and deploying deep learning models using TensorFlow, PyTorch, or similar frameworks.
  • Demonstrated ownership of ML projects from problem framing and data preparation through evaluation, experimentation, production launch, and iteration.
  • Strong command of experimental design and model evaluation, including relationships between offline retrieval metrics and downstream business and user metrics.
  • Experience with large-scale behavioral, contextual, or content datasets and complex feature pipelines.
  • Strong software engineering fundamentals and ability to write clear, reliable, maintainable production code.
  • Technical leadership experience setting direction, leading complex projects, influencing partner teams, and mentoring engineers.
  • Excellent written and verbal communication skills.
  • Preferred: experience with ads retrieval, ad serving, recommendation, search relevance, marketplace optimization, sequential or graph modeling, multimodal signals, ads marketplaces, or applied ML and ranking publications, patents, or industry contributions.
  • Preferred: experience connecting retrieval improvements to ranking, auction, conversion, revenue, or user-experience outcomes and experience with RNNs or Transformers.

Benefits

  • 100% remote opportunity, with hybrid or onsite work available at offices in New York, San Francisco, Los Angeles, and Chicago.
  • Comprehensive healthcare benefits and income replacement programs.
  • 401(k) with employer match.
  • Global benefits supporting workspace, professional development, caregiving, and lifestyle needs.
  • Family planning support, gender-affirming care, and mental health and coaching benefits.
  • Flexible vacation and paid volunteer time off.
  • Generous paid parental leave.
  • Base salary is eligible for additional equity and, depending on the position, commission; compensation figures are excluded from this benefits summary.

Tech Stack

PyTorchTensorFlow

Categories

Reddit

About Reddit

5,001-10,000 employees

Reddit builds a social news and discussion platform organized into user-created forums (“subreddits”) for consumers, creators, and communities. It monetizes primarily through advertising tools for brands and self-serve advertisers, plus a Premium subscription; developers can access data via its API. Founded in 2005 and headquartered in San Francisco, Reddit became a public company on the NYSE in 2024 and hosts over 100,000 active communities.

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