Machine Learning Engineer

Lead the development of large-scale machine learning systems powering Reddit notifications, from data pipelines to online serving and experimentation.

Responsibilities

• Design, build, and maintain scalable machine learning infrastructure supporting notification relevance, targeting, ranking, and personalization across channels (push, email, in-app notifications) for millions of users.
• Architect and implement end-to-end ML pipelines for notifications, including data ingestion, feature computation, model training, evaluation, deployment, and production online serving.
• Partner cross-functionally with data scientists, product managers, and engineers to define requirements, align priorities, and deliver end-to-end notification solutions.
• Lead experimentation framework design and implementation, including A/B testing, multi-armed bandits, or similar approaches to evaluate notification models, ranking strategies, and targeting policies.
• Mentor engineers with technical guidance and share best practices in machine learning engineering, distributed systems, and ML infrastructure design.

Requirements

• Bachelor's degree in Computer Science, Engineering (any field), or a related quantitative discipline.
• Five (5) years of experience in the job offered or related occupation.

Technologies

• Programming: Python, Golang, Java
• ML: PyTorch, TensorFlow
• APIs and communication: REST, HTTP, Thrift, gRPC
• Data, storage, and caching: Redis, Cassandra, DynamoDB
• Messaging and events: Apache Kafka, AWS SQS, AWS SNS, SES
• ML and orchestration: Kubeflow, Ray, Apache Airflow, AWS Step Functions
• Cloud and analytics: Google BigQuery, Amazon Redshift
• Observability: Prometheus, Grafana, AWS Cloudwatch

Special Skill Requirements

• Designing, building, and iterating large-scale scalable software systems.
• Designing and building ML recommender systems at high scale.
• Delivering large and complex systems with significant business impact.
• Cross-functional collaboration on large-scale projects with complex dependencies across teams.
• Object-oriented programming using Python, Golang, or Java.
• Building ML models with PyTorch or TensorFlow.
• API design and integration with REST, HTTP, Thrift, or gRPC.
• Working with large-scale key-value and NoSQL storage and caching systems including Redis, Cassandra, and DynamoDB.
• Working with large-scale messaging and event-driven systems including Apache Kafka, AWS SQS, SNS, and SES.
• Building workflows using Kubeflow, Ray, Apache Airflow, and AWS Step Functions.
• Working with large-scale analytics and data warehousing platforms including Google BigQuery and Amazon Redshift.
• Experience with observability, including logging, tracing, and monitoring tools such as Prometheus, Grafana, and AWS Cloudwatch.
• Designing, running, and analyzing A/B experiments to measure and optimize system performance.

Benefits

• Comprehensive Healthcare Benefits and Income Replacement Programs
• 401k with Employer Match
• Global benefit programs covering workspace, professional development, and caregiving support
• Family Planning Support
• Gender-Affirming Care
• Mental Health & Coaching Benefits
• Flexible Vacation & Paid Volunteer Time Off
• Generous Paid Parental Leave

Compensation

• Base salary range: $230,000.00 - $322,000.00 USD
• Job posting may span more than one career level.
• Eligible for equity in the form of restricted stock units.
• Depending on the position offered, the role may also be eligible for commission.
• U.S.-based benefits include medical, dental, vision insurance, and 401(k) program with employer match.
• #LI-DNI

Interview Recording Notice

• In select roles and locations, interviews will be recorded, transcribed, and summarized by artificial intelligence (AI).
• Opportunity to opt out of recording, transcription, and summarization prior to scheduled interviews.
• During the interview, Reddit will collect: identifiers, professional and employment-related information, sensory information (audio/video recording), and any other categories you choose to share.
• Information will be used to evaluate your application for employment or an independent contractor role.
• Reddit will not sell personal information or disclose it to third parties for their marketing purposes.
• Reddit will delete any recording promptly after making a hiring decision.
• For more details, refer to the Candidate Privacy Policy for Potential Employees and Contractors.

Equal Opportunity Employer

• Reddit is an equal opportunity employer committed to building a workforce representative of the diverse community.
• Reasonable accommodations available for qualified individuals with disabilities and disabled veterans during the job application process.
• If you need accommodation during the interview process, notify your recruiter.

Location: San Francisco, CA (remote). Salary: USD 230,000 - 322,000 per yearly.