Senior Machine Learning Engineer, Ads Training Platform

Reddit is a community of communities. It’s built on shared interests, passion, and trust and is home to the most open and authentic conversations on the internet. Every day, Reddit users submit, vote, and comment on the topics they care most about. With 100,000+ active communities and approximately 101M+ daily active unique visitors, Reddit is one of the internet’s largest sources of information. For more information, visit redditinc.com.

Reddit has a flexible first workforce! if you happen to live close to our physical office location our doors are open for you to come into the office as often as you’d like. Don’t live near one of our offices? No worries: You can apply to work remotely from the Netherlands or the United Kingdom.

Team Overview
The Ads Training Platform pod builds and maintains the distributed training and data processing infrastructure that powers Reddit’s Ads machine learning models. We focus on enabling fast, reliable, and scalable model training across large datasets, supporting the Ads ML teams in improving ad targeting, conversion prediction, and advertiser value.

We are looking for an engineer with deep experience in infrastructure, distributed systems, and ML platform operations to help evolve and scale our training systems.

What You’ll Do

• Design, build, and maintain large-scale distributed training infrastructure for Ads ML models.
• Develop tools and frameworks on top of the Ray platform.
• Build tools to debug, profile, and tune distributed training jobs for performance and reliability.
• Integrate with object storage systems and improve data access patterns.
• Collaborate with ML engineers to improve model training time, efficiency, and GPU training costs..
• Drive improvements in scheduling, state management, and fault tolerance within the training platform to enhance overall performance.

What You Bring

• 5+ years in infrastructure/platform engineering or large-scale distributed systems.
• 2+ years hands-on experience with Ray platform.
• Strong understanding of distributed computing principles (task scheduling, fault tolerance, state management).
• Experience with distributed storage systems and large-scale data processing.
• Proven ability to debug and profile distributed jobs.
• Experience with deep learning frameworks (PyTorch, TensorFlow) is a big plus.
• Bonus: model optimization for distributed training, Ads ML experience.

Benefits:

• Pension Scheme
• Private Medical and Dental Scheme
• Life Assurance, Income Protection
• Workspace benefit for your home office 
• Personal & Professional development funds
• Family Planning Support 
• Commuter Benefits
• Flexible Vacation & Reddit Global Days Off

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.