Build and scale machine learning systems that power Reddit notifications across relevance, targeting, ranking, and personalization.

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

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

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 in 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, AWS SNS, and SES.
Building workflows using orchestration systems including 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, 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.

Languages: Python, Golang, Java
ML Frameworks: PyTorch, TensorFlow
APIs/Protocols: REST, HTTP, Thrift, gRPC
Data Stores/Caching: Redis, Cassandra, DynamoDB
Streaming/Messaging: Apache Kafka, AWS SQS, AWS SNS, SES
ML/Workflow Orchestration: Kubeflow, Ray, Apache Airflow, AWS Step Functions
Analytics/Warehousing: Google BigQuery, Amazon Redshift
Observability: Prometheus, Grafana, AWS Cloudwatch

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

This job posting may span more than one career level.
Eligible for equity in the form of restricted stock units (RSUs).
Depending on the position offered, eligibility for commission may apply.
Reddit offers benefits to U.S.-based employees including medical, dental, vision insurance, 401(k) with employer match, generous time off, and parental leave.
#LI-DNI

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Reddit is an Equal Opportunity Employer committed to building a workforce representative of the diverse community.
Reasonable accommodations are available for qualified individuals with disabilities and disabled veterans in the job application procedures.
If you need an accommodation during the interview process due to a disability, let your recruiter know.

Machine Learning Engineer

Job Description