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Senior Machine Learning Engineer

RedditRemote - Ontario, CanadaMachine Learning
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Salary
Not listed
Job type
Full-time
Work mode
Remote
Posted
14 Aug 2025
Status
Open · checked 7d ago

About this role

Reddit is seeking a remote Senior Machine Learning Engineer in Ontario, Canada, to design and scale core machine learning systems across consumer and ads organizations. This opportunity suits experienced engineers who want to build end-to-end production models and shape the future of discovery on a massive global platform.

Role Overview

Machine learning is central to how millions of people discover content, connect, and engage across Reddit's vast network of communities. In this role, engineers tackle complex applied machine learning problems at internet scale, influencing personalized recommendations, search relevance, advertising systems, and marketplace dynamics. The position offers collaboration across multiple specialized teams, ranging from feed relevance and search to advertiser optimization and foundational representations.

Key Responsibilities

Design, build, and deploy production-grade machine learning models and systems at internet scale.
Own the complete machine learning lifecycle, covering problem definition, feature engineering, training, evaluation, deployment, and monitoring.
Construct scalable data and model pipelines with robust reliability, observability, and automated retraining capabilities.
Partner cross-functionally with product, data science, infrastructure, and engineering teams to translate ambiguous business challenges into technical machine learning solutions.
Optimize system performance regarding latency, throughput, and model quality metrics.
Research and apply state-of-the-art artificial intelligence techniques, including deep learning, transformer-based architectures, and large language model evaluation or alignment.

Requirements

Three to five or more years of professional experience building, deploying, and operating machine learning systems in production environments.
Strong programming skills in languages such as Python or Java, paired with solid software engineering fundamentals.
Thorough grasp of machine learning algorithms, ranging from classic statistical learning methods like XGBoost and random forests to deep learning architectures including transformers and graph neural networks.
Hands-on experience utilizing modern machine learning frameworks such as PyTorch or TensorFlow.
Proven ability to design scalable machine learning pipelines, data processing systems, and model serving infrastructure.

Nice to Have

Practical experience working with recommender systems, search or ranking platforms, advertising and auction systems, or multimodal embedding systems.
Familiarity with distributed systems and large-scale data processing tools including Spark, Kafka, Ray, Airflow, BigQuery, and Redis.
Background in real-time systems and low-latency production environments.
Experience with generative artificial intelligence and large language model techniques, including fine-tuning, knowledge distillation, retrieval-augmented generation, and agentic systems.
Advanced degree in computer science, machine learning, or a related quantitative discipline.

Skills and Tools

Python
PyTorch
TensorFlow
Java
Spark
Large Language Models
Retrieval-Augmented Generation
Kafka
Airflow

About the Company

Reddit is a community of communities built on shared interests, passion, and trust, featuring over 100,000 active communities and approximately 130 million daily active unique visitors. As one of the internet's largest sources of information, the company fosters authentic conversations and powers discovery for millions of users worldwide.

How to Apply

Interested candidates should visit the official Reddit careers page to submit an application for this remote opportunity.

Skills and tech stack

PythonPyTorchTensorFlowJavaSparkLLMRAGKafkaAirflow

Questions candidates ask

Where is this position located?

This role is remote based out of Ontario, Canada.

How many years of experience are required?

The role requires three to five or more years of experience building, deploying, and operating machine learning systems in production.

What core technologies and frameworks are used?

Engineers work with Python, PyTorch, TensorFlow, Java, Spark, Kafka, Airflow, and large language model technologies.

What types of systems will I be building?

You will build personalized recommendations, search and ranking systems, advertising systems, large-scale ML pipelines, and LLM-driven experiences.

How should I apply for this job?

Candidates can apply directly through the official company careers page.

Ready to apply?

The application is on the official Reddit careers page.

Apply on company site