Jobs for data annotator at Toronto

Mercor is hiring experienced Musicians to evaluate generative musical AI models in partnership with a leading AI lab.You will assess model outputs across in different categories of music in your bilingual language.Key ResponsibilitiesEvaluate AI model output lyrics, voice generation, and other standardsScore quality of musical training dataExperience writing...

Aimbient (formerly Surgical Safety Technologies) is a fast-growing healthcare technology start-up located in the heart of Toronto, Canada. The Aimbient Suite is a platform that captures some of the world’s most valuable data from surgery and allows hospitals to identify, understand, and mitigate risk. The Aimbient Platform is implemented in several of the...

At eBay, we're more than a global ecommerce leader — we’re changing the way the world shops and sells. Our platform empowers millions of buyers and sellers in more than 190 markets around the world. We’re committed to pushing boundaries and leaving our mark as we reinvent the future of ecommerce for enthusiasts.Our customers are our compass,...

At eBay, we're more than a global ecommerce leader — we’re changing the way the world shops and sells. Our platform empowers millions of buyers and sellers in more than 190 markets around the world. We’re committed to pushing boundaries and leaving our mark as we reinvent the future of ecommerce for enthusiasts.Our customers are our compass,...

**Principal Python Engineer — ML Infrastructure (AI Training)** **About The Role** What if your Python expertise could directly shape the infrastructure that powers the most advanced AI systems in the world? We're looking for a Principal Python Engineer in Toronto to design and build the data pipelines, annotation tooling, and evaluation systems that...

**Computer Vision & ML Expert (AI Training)** **About The Role** What if your expertise in computer vision could directly shape how the next generation of AI systems perceives, interprets, and understands the visual world? We're looking for Computer Vision & Machine Learning Experts in the Toronto area and across Canada to evaluate, improve, and guide AI...

**Who are we?** Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread...

**Who are we?** Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread...

**Who are we?** Our mission is to scale intelligence to serve humanity. We’re training and deploying frontier models for developers and enterprises who are building AI systems to power magical experiences like content generation, semantic search, RAG, and agents. We believe that our work is instrumental to the widespread adoption of AI. We obsess...

**About The Role** What if your deep knowledge of formal mathematics could directly shape how the most advanced AI systems in the world reason, prove, and think? We're looking for mathematicians with a passion for rigorous proof and formal systems to help build the mathematical foundations that frontier AI depends on. This is a fully remote, flexible...

**Mechanical Engineering — AI Trainer** **About The Role** We're partnering with the world's leading AI research labs to build smarter, more technically rigorous AI models — and we need mechanical engineers to make it happen. If you have deep knowledge of fluid dynamics, thermodynamics, structural mechanics, or mechatronics, this is your opportunity to...

**About The Role** What if your deep expertise in TypeScript could directly influence how AI writes code for millions of developers around the world? We're looking for experienced Frontend TypeScript Engineers in Toronto and across Canada to review, evaluate, and guide AI-generated code — helping cutting-edge AI models understand what truly type-safe,...

**About Rex.zone** Rex.zone is hiring Toronto-based candidates for full-time remote data annotation and data labeling work that improves training data quality for AI/ML systems. You will support real-world LLM training pipelines through evaluation, QA, and careful rubric-driven judgments. **About The Role** As a Remote Data Annotator, you will create...

About the roleAs our Technical Content Writer, you will be the strategic architect and hands-on creator for our most viewed self-serve help channel, the Help Desk. You are not just a writer—you will completely own, organize, and scale our customer-facing Help Center/Knowledge Base.You will bridge the gap between complex platform mechanics and clear,...

Rex.zone is hiring senior contributors to lead AI data annotation and QA evaluation workstreams that improve training data quality for modern AI/ML systems. This is a **remote** , **full-time** role aligned to real-world LLM training pipelines across NLP, computer vision, and content safety domains. **About The Role** You will translate product and...

In this hourly, remote contractor role, you will review AI-generated English-language responses and/or generate expert language content, evaluating reasoning quality and step-by-step edits while providing precise, actionable feedback. You will assess solutions for accuracy, clarity, and adherence to the prompt; identify errors in logic, meaning, methodology,...

**Who are we?** Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread...

At eBay, we're more than a global ecommerce leader — we’re changing the way the world shops and sells. Our platform empowers millions of buyers and sellers in more than 190 markets around the world. We’re committed to pushing boundaries and leaving our mark as we reinvent the future of ecommerce for enthusiasts.Our customers are our compass,...

UHN is Canada’s #1 hospital and the world’s #1 publicly funded hospital. With 10 sites and more than 44,000 TeamUHN members, UHN consists of Toronto General Hospital, Toronto Western Hospital, Princess Margaret Cancer Centre, Toronto Rehabilitation Institute, The Michener Institute of Education and West Park Healthcare Centre. As Canada's top research...

AI & Robotics Intern Scarborough, ON & Pickering, ON | Internship (4 to 8 months) | Student (completed or in progress) About us In Trench Canada, we deliver state-of-the-art, safe, and reliable instrument transformers, coils, and bushings for seamless energy transmission. With a legacy of customized engineering and innovation, we enable society to harness...