Senior Machine Learning Engineer - Notifications Relevance - Remote

Overview

We’re looking for a Senior Machine Learning Engineer to join the Notifications Relevance team. Our goal: deliver the right content to the right user at the right time through push, email, and in-app notifications. This is a high-impact team driving DAU growth and long-term user retention by connecting users to what matters most to them.

In Short

• Tackle unique ML challenges at Reddit scale: recommend from hundreds of millions of posts, optimize across channels, and balance relevance, timeliness, and user fatigue.
• Build and productionize large-scale retrieval, ranking, and budgeting models that personalize notifications for tens of millions of users.
• Work across the full stack - from designing deep learning models to scaling distributed training and inference pipelines.
• Collaborate closely with product, data science, and infra teams to drive measurable engagement outcomes (DAU, CTR, retention).

Requirements

• 5+ years of industry experience (post-internship) working on large-scale machine learning systems.
• Hands-on experience building, deploying, and scaling recommender systems (retrieval + ranking) in production.
• Deep understanding of system-level trade-offs in large-scale recommendation pipelines.
• Proficiency in Python; familiarity with frameworks like PyTorch or TensorFlow.
• Experience with distributed training and inference using tools like Ray, PyTorch Distributed, or similar.

Benefits

• Comprehensive Healthcare Benefits and Income Replacement Programs
• 401k Match
• Family Planning Support
• Gender-Affirming Care
• Mental Health & Coaching Benefits
• Flexible Vacation & Reddit Global Days off
• Generous paid Parental Leave
• Paid Volunteer time off