Reddit is seeking a Senior Machine Learning Engineer to design and build production ML systems that power core experiences across our platform, including personalized recommendations, search, ranking, and advertising. You will own the full ML lifecycle from problem definition to deployment and monitoring, working on high-impact systems that operate at internet scale.

What You'll Do

Design, build, and deploy production-grade machine learning models and systems at scale.
Own the full ML lifecycle: from problem definition and feature engineering to training, evaluation, deployment, and monitoring.
Build scalable data and model pipelines with strong reliability, observability, and automated retraining.
Work with large-scale datasets to improve ranking, recommendations, search relevance, prediction, content/user understanding, and optimization systems.
Partner cross-functionally with Product, Data Science, Infrastructure, and Engineering teams to translate complex problems into ML solutions.
Improve system performance across latency, throughput, and model quality metrics.
Research and apply state-of-the-art machine learning and AI techniques, including deep learning, graph & transformers based, and LLM evaluation/alignment.
Contribute to technical strategy, architecture, and long-term ML roadmap.

What We're Looking For

3-5+ years of experience building, deploying, and operating machine learning systems in production.
Strong programming skills in Python, Java, Go, or similar languages, with solid software engineering fundamentals.
Strong grasp of ML algorithms, from classic statistical learning (XGBoost, Random Forests, regressions) to DL architectures (Transformers, CNNs, GNNs).
Hands-on experience with modern ML frameworks (e.g., PyTorch, TensorFlow).
Experience designing scalable ML pipelines, data processing systems, and model serving infrastructure.
Ability to work cross-functionally and translate ambiguous product or business problems into technical solutions.
Experience improving measurable metrics through applied machine learning.

Nice to Have

Experience with recommender systems, search/ranking systems, advertising/auction systems, large-scale representation learning, or multimodal embedding systems.
Familiarity with distributed systems and large-scale data processing (Spark, Kafka, Ray, Airflow, BigQuery, Redis, etc.).
Experience working with real-time systems and low-latency production environments.
Background in feature engineering, model optimization, and production monitoring.
Experience with LLM/Gen AI techniques, including but not limited to LLM evaluation, alignment, fine-tuning, knowledge distillation, RAG/agentic systems and productionizing LLM-powered products at scale.
Advanced degree in Computer Science, Machine Learning, or a related quantitative field.

Technical Stack

Languages: Python, Java, Go
ML Frameworks: PyTorch, TensorFlow
Data & Infrastructure: Spark, Kafka, Ray, Airflow, BigQuery, Redis

Team & Environment

You will be hired across both Consumer and Ads organizations at Reddit, partnering closely with Product, Data Science, Infrastructure, and Engineering teams.

Benefits & Compensation

Salary range: $185,800 - $303,400 USD plus equity in the form of restricted stock units.
Comprehensive Healthcare Benefits and Income Replacement Programs.
401k with Employer Match.
Global Benefit programs that fit your lifestyle, from workspace to professional development to caregiving support.
Family Planning Support and Gender-Affirming Care.
Mental Health & Coaching Benefits.
Flexible Vacation & Paid Volunteer Time Off.
Generous Paid Parental Leave.

Work Mode

This is a fully remote position open to candidates located within the United States.

Reddit is proud to be an equal opportunity employer and is committed to building a workforce representative of the diverse communities we serve. We are committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures.