Senior Machine Learning Engineer

Stack

Responsibilities

• ▹Design, build, and deploy production-grade machine learning models and systems at scale
• ▹Own the full ML lifecycle: problem definition, feature engineering, training, evaluation, deployment, 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, and content/user understanding
• ▹Partner cross-functionally with Product, Data Science, Infrastructure, and Engineering teams
• ▹Improve system performance across latency, throughput, and model quality
• ▹Research and apply state-of-the-art ML and AI techniques: deep learning, graph & transformer-based methods, LLM evaluation/alignment
• ▹Contribute to technical strategy, architecture, and the long-term ML roadmap

Requirements

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

Nice to have

• ▹Experience with recommender systems, search/ranking, advertising/auction systems, or large-scale representation learning
• ▹Familiarity with distributed systems and large-scale data processing (Spark, Kafka, Ray, Airflow, BigQuery, Redis, etc.)
• ▹Experience with real-time systems and low-latency production environments
• ▹Background in feature engineering, model optimization, and production monitoring
• ▹Experience with LLM/Gen AI techniques: evaluation, alignment, fine-tuning, knowledge distillation, RAG/agentic systems
• ▹Advanced degree in Computer Science, Machine Learning, or related quantitative field

Soft skills

What we offer

• ▹Comprehensive healthcare benefits and income replacement programs
• ▹401k with employer match
• ▹Global benefit programs
• ▹Family planning support
• ▹Gender-affirming care
• ▹Mental health & coaching benefits
• ▹Flexible vacation & paid volunteer time off
• ▹Generous paid parental leave

About the company

Reddit is a community of communities where people share, discuss, and vote on the topics they care about. With 100,000+ active communities and approximately 126 million daily unique visitors, Reddit is one of the internet's largest sources of information. Machine learning is central to how Reddit powers personalized recommendations, search, and advertising systems.