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Machine Learning Engineer



Software Engineering
Toronto, ON, Canada · Remote
Posted on Friday, May 17, 2024

What we do:

Zefr is the global leader in brand suitability targeting and measurement across the world’s largest platforms. Zefr’s technology is helping to power the age of responsible marketing by putting advertisers in control of their content adjacencies based on their own unique brand safety and suitability preferences, mapped to the Global Alliance of Responsible Media’s (GARM) industry standards. As an official YouTube Measurement Program Partner, Meta for Business Partner, and TikTok for Business Partner, the company leverages patented machine learning and AI technology (Cognition AI) to offer brands and agencies more precise and transparent brand safety and suitability activation and measurement solutions on scaled platforms. The company is headquartered in Los Angeles, California, with additional locations across the globe.

What you’ll do:

We are hiring a Machine Learning Engineer focused on algorithm development and implementation for natural language processing and computer vision classifiers. These classifiers are applied to tens of millions of social media posts daily! You will be working with state of the art transformer models, as well as large language models, to build sophisticated compound AI systems. Additionally we work with semantic and image similarity search, leveraging vector databases storing hundreds of millions of content embeddings to find relevant data! You will be expected to work with all of these components, balancing cost and quality to develop the best performing classifiers possible! We are excited to welcome someone who is passionate about cutting edge research in machine learning and computer vision. We want an individual who can keep up to date with the ever-expanding field of Data Science. This is a role where we both expect to learn from you and have you learn from us!

Tech stack:

  • Languages: Python, SQL
  • Data Stores: Snowflake, Qdrant, OpenSearch, ScyllaDB
  • Data Processing: Apache Kafka, Pandas, DBT, FastAPI, Parquet
  • DevOps: Github Actions, Docker, Terraform, Kubernetes, ArgoCD, AWS, GCP, Datadog
  • MLOps:Triton Inference Server, Weights and Biases, Transformers, Onnx, TensorRT, DVC, HuggingFace, VertexAI

What we’re looking for:

  • Bachelor's or Master's degree in Computer Science or related field with 2+ years of professional experience
  • Strong Data Science background
  • Fluency with Python and SQL (Specifically Snowflake)
  • Experience working with and developing neural networks
  • Experience with working with Large language models, vector search and RAG systems
  • Strong foundation in data structures, algorithms and software design
  • Thorough testing and code review standards/practices
  • Strong verbal and written communication skills
  • Openness to new technologies and creative solutions

Zefr is an equal opportunity employer that embraces diversity and inclusion in the workplace. We are committed to building a team that represents a variety of backgrounds, skills, and perspectives because we know this only makes us better. We strongly encourage women, persons of color, LGBTQIA+ individuals, persons with disabilities, members of ethnic minorities, foreign-born residents, and veterans to apply even if you do not meet 100% of the qualifications.


The anticipated salary for this position is between $140,000 and $165,000 USD. Within the range, individual pay is determined by factors such as job-related skills, experience, and relevant education or training. If your compensation expectations fall outside of this range, it may still be worth having a conversation.