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.
Why this role?- 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).
- Research, prototype, and productionize retrieval and ranking models that power personalized notifications at scale.
- Design and build large-scale systems - from model pipelines to real-time serving - that handle Reddit’s massive user base and content volume.
- Drive architecture decisions and roadmap priorities for the team’s ML systems.
- Lead experimentation efforts, measure impact rigorously (offline + A/B), and iterate quickly.
- Mentor other engineers and contribute to building a high-quality, collaborative ML culture.
- 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 (e.g. latency, throughput, storage of embeddings, feature freshness).
- Proficiency in Python; familiarity with frameworks like PyTorch or TensorFlow.
- Experience with distributed training and inference using tools like Ray, PyTorch Distributed, or similar.
- Experience developing sequential modeling and real-time systems.
- Familiarity with reinforcement learning or multi-objective optimization in recommendation systems.
- Experience with orchestration tools (e.g. Airflow, Kubeflow), large-scale data processing (e.g., BigQuery, Dataflow).
- MS or PhD in Computer Science or a related field.
Reddit has a flexible first workforce. This role is 100% remote, and open only to candidates currently located within the United States.
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
Pay Transparency:
This job posting may span more than one career level.
In addition to base salary, this job is eligible to receive equity in the form of restricted stock units, and depending on the position offered, it may also be eligible to receive a commission. Additionally, Reddit offers a wide range of benefits to U.S.-based employees, including medical, dental, and vision insurance, 401(k) program with employer match, generous time off for vacation, and parental leave. To learn more, please visit https://www.redditinc.com/careers/.
To provide greater transparency to candidates, we share base pay ranges for all US-based job postings regardless of state. We set standard base pay ranges for all roles based on function, level, and country location, benchmarked against similar stage growth companies. Final offer amounts are determined by multiple factors including, skills, depth of work experience and relevant licenses/credentials, and may vary from the amounts listed below.
In select roles and locations, the interviews will be recorded, and transcribed and summarized by artificial intelligence (AI). You will have the opportunity to opt out recording, transcription and summarization prior to any scheduled interviews.
During the interview, we will collect the following categories of personal information: Identifiers, Professional and Employment-Related Information, Sensory Information (audio/video recording), and any other categories of personal information you choose to share with us. We will use this information to evaluate your application for employment or an independent contractor role, as applicable. We will not sell your personal information or disclose it to any third party for their marketing purposes. We will delete any recording of your interview promptly after making a hiring decision. For more information about how we will handle your personal information, including our retention of it, please refer to our Candidate Privacy Policy for Potential Employees and Contractors.
Reddit is proud to be an equal opportunity employer, and is committed to building a workforce representative of the diverse communities we serve. Reddit is committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures. If, due to a disability, you need an accommodation during the interview process, please let your recruiter know.
Similar Jobs
What We Do
Reddit is a community of millions of users engaging in the creation of content and the sharing of conversation across tens of thousands of topics. Our mission is to bring community, belonging, and empowerment to everyone in the world.
Why Work With Us
At Reddit, you’ll help build something that encourages millions around the world to think more, do more, learn more, feel more– and maybe even laugh more.
Gallery
