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 adoption of AI and we are looking for folks that want to be part of that. We obsess over what we build. Each one of us is responsible for contributing to increasing the capabilities of our models and the value they drive for our customers. Cohere is a team of researchers, engineers, designers, and more, who are all passionate about their craft. We are a global technology company headquartered in Toronto with key offices in London, New York City, San Francisco, Montreal, Paris, Berlin and Seoul. Join us! Why this role? Evaluation is critical to making progress in scaling intelligence. As models continue to become superhuman in many real-world use cases, we must continue to develop new evaluation techniques that accurately reflect what models are already capable of, as well as set the agenda for what future models should be capable of. In this role, you are responsible for creating these next-generation evaluation methods and infrastructure to measure LLM progress. As a Senior Research Scientist, Model Evaluation, you will: Create ambitious new evaluation benchmarks that push the limits of what our models can accomplish. Work on highly cross-functional teams to translate model feedback into trustworthy, repeatable evaluations. Conduct research to advance the state-of-the-art in LLM evaluation methods, including training LLM judges; refining LLM-based data synthesis pipelines; and improving evaluation efficiency. Build scalable and reusable tools for digging into model performance. You may be a good fit if: You enjoy rapidly building prototypes that demonstrate the boundaries of what LLMs are capable of, and you have developed res
Jobs in Canada
Senior Scientist Team Lead in Toronto
167 active opportunities · Updated October 2026
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Explore current senior scientist team lead jobs in Toronto. Filter by work mode, employment type, experience, department, date posted and distance.
Reddit is a community of communities. It’s built on shared interests, passion, and trust, and is home to the most open and authentic conversations on the internet. Every day, Reddit users submit, vote, and comment on the topics they care most about. With 100,000+ active communities and approximately 130 million daily active unique visitors, Reddit is one of the internet’s largest sources of information. For more information, visit www.redditinc.com . Reddit’s Ads Data Science team is looking for a Senior Staff Data Scientist to lead the scientific strategy behind Reddit’s ads measurement and signal systems. This role sits at the center of how Reddit proves advertiser value, improves signal quality, builds privacy-aware measurement systems, and connects ads exposure to real advertiser outcomes. As a Senior Staff Data Scientist for Ads Measurement, you will be the principal architect of our technical vision and the driving force behind the next generation of our measurement ecosystem. In a landscape rapidly shifting due to privacy regulations, browser changes, and evolving platform dynamics, you will spearhead innovation across experimental design (incrementality/lift), identity, signals, and privacy-safe 1P/3P measurement. This is a high-visibility, high-impact role requiring a rare blend of deep experimentation & causal inference expertise, strategic foresight, and the ability to influence cross-functional executives and industry standards. You will not just adapt to the changing ad-tech environment, you will redefine how we measure value. Responsibilities Technical Vision & Strategy: Define the long-term data science vision & strategy across ads measurement, signal quality, identity, attribution, and privacy. Establish how Reddit should evaluate advertiser value, measurement quality, and signal utility across first-party and third-party products. Set the Cross-Pillar Measurement Science Strategy: Define the long-term data science strategy across a
At Lyft, our purpose is to serve and connect. We aim to achieve this by cultivating a work environment where all team members belong and have the opportunity to thrive. As a Senior Software Engineer, Data on the Mapping team, you will collaborate with our world-class team of engineers, product managers, and scientists to grow and improve the quality of recommended routes and accuracy of our travel time estimations. You will lead the architecture and long-term technical direction of our offline experimentation tooling and route simulation services — the systems that let Lyft test routing changes safely before they reach production. You'll also build scalable data pipelines for experimentation, analytics, and machine learning models, along with the data governance and observability systems that keep them trustworthy. Your work will enable integration with partner teams and allow stakeholders across Engineering, Data Science, and Product to make data-informed decisions that directly impact Lyft’s growth and profitability. Our technology stack is based on the latest technologies such as AWS, Databricks, Kubernetes and Airflow. You will work with incredibly passionate and talented colleagues from software engineering, machine learning and data science on projects that directly impact millions of riders and drivers. Responsibilities Own core data pipelines end-to-end, building deep subject matter expertise in the systems you manage and defining/managing SLAs for pipelines, services, and datasets to ensure reliability at scale Serve as the technical owner and architectural lead for our offline experimentation platform and route simulation services, setting technical direction, evaluating trade-offs, and ensuring the systems scale with Lyft's routing and mapping ambitions Continuously evolve data models and schemas to meet business and engineering requirements Develop AI tools that support self-service management of data pipelines (ETL) and schema evolution, and perform han
From C$136K/yr
At Lyft, our purpose is to serve and connect. We aim to achieve this by cultivating a work environment where all team members belong and have the opportunity to thrive. Our team is dedicated to creating a seamless and secure experience for our riders and drivers, ensuring their identity and data are protected at all times. As a Senior Product Designer, you'll lead the design of solutions that help drivers understand their earnings and get paid securely while protecting our communities from fraud. You will work closely with cross-functional teams, including product managers, designers, engineers, and data scientists, to create intuitive and effective designs on driver payments and complex security challenges. You’ll advocate for a customer-centric approach and thrive in a dynamic, fast-paced environment. From initial ideation through to launch, you'll support projects with interaction, visual, and product thinking skills, helping to define and deliver impactful experiences for our Payment, Identity and Integrity teams. The Opportunity Design features that help drivers understand their earnings, access their pay, and resolve payment issues efficiently Lead end-to-end design for driver earnings and identity verification experiences, from research and ideation through execution Play a critical role in designing solutions that protect our users and enhance their trust in our platform Collaborate with cross-functional partners to design intuitive and effective designs that address unique rideshare driver, identity and fraud challenges Responsibilities: Problem solve, think big, and explore divergent concepts/ideas while understanding how to converge and build iteratively towards your vision. Influence the shape of the product with research and data while executing design work using high quality wireframes, mockups, user journeys, and cross-platform interactive prototypes. Advocate for design by sharing your work and presenting cross-functionally, while being able to
From C$136K/yr
At Lyft, our purpose is to serve and connect. We aim to achieve this by cultivating a work environment where all team members belong and have the opportunity to thrive. Lyft is looking for experienced software engineers from a variety of disciplines. We are growing our team with people who want to build, improve and incorporate technologies that make the lives of our community more enriched. As an engineer at Lyft, you'll collaborate with teams like product, data science, analytics, and operations on code that empower us to iterate quickly, while focusing on delighting our passengers and drivers. As a Senior Software Engineer on the Marketplace team, you will lead work streams to improve business operations in Lyft’s Marketplace. You'll design AI driven data analytics platforms, data pipelines and metric governance systems that our business leaders use on a daily basis to make key strategic decisions. You will partner with business leaders and data scientists across our organizations to enable running the business more efficiently. Responsibilities: Help define the roadmap and architecture based on technology and business needs Drive AI innovation for business analytics and operations Write well-crafted, well-tested, readable, maintainable code Have a good grasp and ability to explain the various tradeoffs made in decisions Participate in code reviews to ensure code quality and distribute knowledge Lead projects from idea to positive execution Incorporate considerations for business context and failure modes in your work Proactively participate in resolving ongoing incidents Unblock, support, effectively communicate, and obtain buy-in across teams to achieve results Share your knowledge by giving brown bags, tech talks, and evangelizing appropriate tech and engineering best practices Experience: 5+ years of software engineering industry experience with a high level programming language (bonus points for experience with Python or Go) AI Experience in Agen
From C$1.2M/yr
About the Role: Tubi is seeking a highly skilled and experienced Senior QA Automation Engineer to lead quality assurance initiatives for our cutting-edge streaming and AI-driven product features. This pivotal role involves ensuring exceptional end-to-end user experiences, robust streaming playback, and the accuracy and integrity of our AI/ML features across web, mobile, and OTT platforms. We're looking for a candidate with a strong background in streaming QA and deep technical knowledge of media workflows. You'll be instrumental in collaborating with engineering, product, and data science teams to define comprehensive QA strategies that guarantee both functional excellence and data-level quality. This is a hybrid role based out of our Toronto office. You must be willing to travel to our Toronto office three days/week. What You'll Do: Design and lead test strategies for streaming workflows, playback systems, and AI-powered features. Test across platforms (web, mobile, and connected TV) to ensure functional parity and playback stability. Validate streaming performance—including ABR logic, encoding pipelines, and DRM integrations—under diverse real-world conditions. Debug with precision using tools like Charles Proxy, Chrome DevTools, ADB, and Xcode. Collaborate with data and ML teams to validate AI model updates, recommendations, and personalization accuracy. Leverage AI-assisted QA tools to enhance regression coverage, UI validation, and anomaly detection. Contribute to automation and CI/CD frameworks, driving faster, more reliable releases. Help drive a shift-left testing approach by engaging early in the software development lifecycle, partnering with product managers, engineers, and data scientists to identify quality risks, define test strategies, and ensure testability during requirements and design phases. Oversee QA deliverables for multiple concurrent releases and ensure seamless sign-off for production launches. Monitor live environments for playback or reco
Our Purpose Mastercard powers economies and empowers people in 200+ countries and territories worldwide. Together with our customers, we’re helping build a sustainable economy where everyone can prosper. We support a wide range of digital payments choices, making transactions secure, simple, smart and accessible. Our technology and innovation, partnerships and networks combine to deliver a unique set of products and services that help people, businesses and governments realize their greatest potential. Title and Summary Senior Analyst, Customer Performance, Brand-1 Overview Mastercard operates the world’s fastest payment processing network, connecting consumers, financial institutions, merchants, governments, and businesses in more than 210 countries and territories. Every day, everywhere, we use our technology and expertise to make payments safe, simple and smart. We know safety and security are the top priorities of our customers, cardholders and partners, so we won’t stand still in developing new and better ways to keep payments safe. • Do you have experience conducting investigations, reviewing evidence, and documenting case outcomes? • Do you have knowledge of merchant onboarding, monitoring, customer response review, and potential Mastercard Standards violations? • Are you a high performer with strong analytical, documentation, and project management skills? • Are you collaborative, detail-oriented, and able to support credible investigations in a fast-paced environment? Mastercard’s Franchise Brand Performance Team advances ecosystem health and profitability by engaging our customers to optimize performance and to enhance the strength of our brand, acceptance network, and data. Role • Preserve the integrity of the Mastercard brand by conducting investigative case work under the Business Risk Assess
Secure Every Identity, from AI to Human Identity is the key to unlocking the potential of AI. Okta secures AI by building the trusted, neutral infrastructure that enables organizations to safely embrace this new era. This work requires a relentless drive to solve complex challenges with real-world stakes. We are looking for builders and owners who operate with speed and urgency and execute with excellence. This is an opportunity to do career-defining work. We're all in on this mission. If you are too, let's talk. Senior Engineering Manager, SDET — Okta Identity Governance (OIG) Secure Every Identity, from AI to Human Identity is the key to unlocking the potential of AI. Okta secures AI by building the trusted, neutral infrastructure that enables organizations to safely embrace this new era. This work requires a relentless drive to solve complex challenges with real-world stakes. We are looking for builders and owners who operate with speed and urgency and execute with excellence. This is an opportunity to do career-defining work. We're all in on this mission. If you are too, let's talk. The Okta Identity Governance Team Okta Identity Governance (OIG) is Okta's Identity Governance and Administration solution, responsible for some of the most critical and visible workflows in enterprise identity: how people request access, how approvers grant it, how entitlements are enforced, and how organizations prove to auditors that only the right people have the right access. OIG is the leading contributor to Okta's new product bookings, and it runs inside some of the largest enterprises in the world — the kind of accounts where a single tenant carries hundreds of thousands of identities across thousands of applications. Quality here is a compliance bar, not just a user experience one. When a governance product has a defect, a company can stay over-provisioned on access it believes it revoked, or hand an auditor evidence that isn't true. The Senior Engineering Manager, SDET Oppo
Secure Every Identity, from AI to Human Identity is the key to unlocking the potential of AI. Okta secures AI by building the trusted, neutral infrastructure that enables organizations to safely embrace this new era. This work requires a relentless drive to solve complex challenges with real-world stakes. We are looking for builders and owners who operate with speed and urgency and execute with excellence. This is an opportunity to do career-defining work. We're all in on this mission. If you are too, let's talk. The Okta Privileged Access Management (PAM) is an identity-centric approach to a common and critical privileged access use case. Our elegant Zero Trust architecture is purpose-built for the modern cloud and helps customers solve challenging security and operations pain points at scale. We are looking for a software engineer to join our fast-growing team with a focus on scalability, reliability, and enhancing the core building blocks of the product. In this role you will: Be deeply involved in evolving the core architecture of PAM. Work in our product development teams to build scalable, composable components of our platform. Be responsible for designing and implementing scalable architecture patterns. Delight our customers by providing world class UX using our React-based design system Design and build APIs that customers rely on for access to production infrastructure. Work on backend components written in Go and frontend components written in React. You might be a good fit if you: Have 3-5 years of software development experience with a background in Golang or similar programming languages. Proficient in React or similar front-end UI stacks. Experienced working with relational databases like PostgreSQL or similar RDBMS technologies. have the ability to complete a feature end to end from designing database models to backend APIs and frontend UI components. Experienced working with any cloud provider such as AWS, GCP or Azure. Thrive in a collaborativ
Secure Every Identity, from AI to Human Identity is the key to unlocking the potential of AI. Okta secures AI by building the trusted, neutral infrastructure that enables organizations to safely embrace this new era. This work requires a relentless drive to solve complex challenges with real-world stakes. We are looking for builders and owners who operate with speed and urgency and execute with excellence. This is an opportunity to do career-defining work. We're all in on this mission. If you are too, let's talk. The Data Enablement Team Auth0 is an easy-to-implement authentication and authorization platform designed by developers for developers. We make access to applications safe, secure, and seamless for the more than 100 million daily logins around the world. Our modern approach to identity enables this Tier 0 global service to deliver convenience, privacy, and security so customers can focus on innovation. Within the Data organization, the Data Enablement team is chartered with creating scalable semantic models that make it safe for anyone to see and understand data. By partnering with product and engineering leaders, this team owns the data lifecycle from strategy to prototyping to implementation, executive dashboard and product level self-service support. The Senior Data Analyst Opportunity Reporting to the Manager, Data Enablement - this role will be responsible for unlocking analytics across the company. You will do this through a combination of data lifecycle ownership, data tooling enablement and outreach programs designed to foster the safe usage of scalable data models for reporting and analytic consumption. You'll serve as a critical data and technical partner that empowers our Sales, TAM, and Customer Success teams with the deep product insights they need to succeed. An average week will find you partnering with these teams to understand their measurement needs, reviewing engineering plans to ensure we capture critical data signals from the Auth
At Lyft, our purpose is to serve and connect, cultivating an inclusive environment where all team members can thrive. As the Business Systems Lead for Payroll & Time, you will lead Lyft's global migration onto Dayforce following recent acquisitions. Sitting within People Technology in Corporate Engineering and IT (CEIT), you'll join Lyft's Dayforce program at a formative moment: the initial rollout spans 12–15 countries over two-plus years, and you're joining early enough to directly shape how implementation, governance, and vendor management get done — not inherit a playbook someone else already wrote. You'll be backed by a mature, experienced Payroll Operations team who bring deep subject-matter expertise, while you own the technical and functional side: driving requirements, directing our systems integrator, and building the governance and vendor management model you'll run long-term as the platform's product/service owner. Sitting within People Technology in CEIT, you will drive requirements, make key functional decisions, and partner closely with Payroll Operations, HR, Legal, and Finance. You'll lead vendor delivery to ensure accurate, compliant payroll and time tracking across each migration wave, then own platform governance and vendor management long-term once the program stabilizes. We're looking for someone who can act as the translation layer between operations, executives, and technical teams — equally comfortable explaining payroll concepts to engineers and system constraints to business stakeholders. Responsibilities: Own Requirements and Direct the Implementation Partner Serve as the internal functional owner for the Dayforce payroll and time migration, driving requirements and directing the systems integrator partner. Translate payroll policy, collective bargaining terms, and statutory requirements — as defined by Payroll Operations and Legal — into actionable technical specifications. Validate vendor configurations against country-specific rule
Secure Every Identity, from AI to Human Identity is the key to unlocking the potential of AI. Okta secures AI by building the trusted, neutral infrastructure that enables organizations to safely embrace this new era. This work requires a relentless drive to solve complex challenges with real-world stakes. We are looking for builders and owners who operate with speed and urgency and execute with excellence. This is an opportunity to do career-defining work. We're all in on this mission. If you are too, let's talk. We are looking for an experienced Staff Software Engineer in Test to join our Identity Management Engineering (IDM) team serving the Privileged Access Team (PAM). This team is passionate about delivering large-scale, mission-critical software in a fast-paced Agile environment. In this role you'll be working with a team of highly-skilled and talented engineers, responsible for delivering sophisticated backend solutions that help Okta reliably operate at large scale and be highly available. As part of the team, you’ll be ensuring projects are completed with the highest quality and reliability using automation at every level for fast, robust and secure releases. Job Duties and Responsibilities: Review requirements and design specs to develop relative test plans and test cases Automate API tests, end-to-end tests, reliability/scale tests Work with engineering management to scope and plan engineering efforts Communicate and document QE plans for scrum teams to review Review application code, identify bug and other areas of weakness, architect tools for future coverage Automate all critical features to maintain zero-debt cadence Release features with solid quality Respond to production issues/alerts and customer issues during on-call rotation Be a strong customer advocate with a strong quality DNA. Requirements: 5+ years of QE experience preferably in an enterprise SaaS company 3+ years experience in quality engineering for enterprise level software. 5+ yea
Secure Every Identity, from AI to Human Identity is the key to unlocking the potential of AI. Okta secures AI by building the trusted, neutral infrastructure that enables organizations to safely embrace this new era. This work requires a relentless drive to solve complex challenges with real-world stakes. We are looking for builders and owners who operate with speed and urgency and execute with excellence. This is an opportunity to do career-defining work. We're all in on this mission. If you are too, let's talk. The Okta Privileged Access Management (PAM) is an identity-centric approach to a common and critical privileged access use case. Our elegant Zero Trust architecture is purpose-built for the modern cloud and helps customers solve challenging security and operations pain points at scale. We're looking for a Senior level Platform Engineer to join a team of highly skilled and talented team players who are proud of what they own and deliver. Our elite team is fast, creative, and flexible; with a weekly release cycle and individual ownership, we expect great things from our engineers and reward them with stimulating new projects, new technologies, and the chance to have significant equity in a company that is changing the cloud computing landscape forever. What you’ll do Leverage cutting-edge AI pair-programmers and LLMs (such as Copilot and Claude) to accelerate the development of secure, enterprise-grade Privileged Access Management (PAM) products. Work with engineering teams to design, develop and deliver cloud-based infrastructure projects on a modern tech stack (Kubernetes/EKS, RDS, DynamoDB, Kinesis, MKS, Redis, OpenSearch, Docker, Terraform on AWS) Drive evaluation, development, and rollout of microservices Operate, support, and upgrade shared services and frameworks. Scale these as their usage invariably grows along with Okta's business. Evaluate and scale existing systems to meet specialized requirements and support Okta’s future business ne
At Lyft, our purpose is to serve and connect. We aim to achieve this by cultivating a work environment where all team members belong and have the opportunity to thrive. Lyft is looking for software engineers from a scope of disciplines. We are growing our team with people who want to build, improve and incorporate technologies that make the lives of our community more enriched. As an engineer at Lyft, you'll collaborate with teams like product, data science, analytics, and operations on code that empower us to iterate quickly, while focusing on delighting our passengers and drivers. The Rider organization is focused on building a seamless, best-in-class rideshare experience for riders. From the foundational functionality of requesting a ride to the tailored interactions with your flight, we sweat the small stuff to help make Lyft the best transportation solution. As an Senior Software Engineer on the Rider Team, you will work hand in hand with various teams across Lyft, fostering collaboration, and driving innovation to improve riders' experience with rideshare. Responsibilities: Write well-crafted, well-tested, readable, maintainable code Participate in code reviews to ensure code quality and distribute knowledge Participate in our teams oncall rotation. Identify, triage, debug and resolve issues/bugs across our various applications and platforms Have the ability to explain the various trade offs made in decisions Manage project priorities, deadlines, and deliverables. Partner with product managers, designers, and other engineering teams to build complex features and products from idea to positive execution Analyze our internal systems and processes and locate areas for improvement/automation Share your knowledge by giving brown bags, tech talks, and promoting appropriate tech and engineering best practices Provide technical mentorship and feedback to junior engineers Help establish roadmap and architecture based on technology and our needs Experience: B
At Lyft, our purpose is to serve and connect. We aim to achieve this by cultivating a work environment where all team members belong and have the opportunity to thrive. The Senior Manager, Marketing Operations and Strategy is responsible for ensuring marketing efforts are efficient, data-driven, and aligned with business goals through process optimization, technology management, and strategic planning. Key duties include managing budget and org health, leading org-wide annual planning process, managing quarterly reporting (QBRs), overseeing campaign execution and budget, and providing overall operations support to the marketing leadership team. Responsibilities: Strategic planning: Developing and implementing marketing strategies and plans to achieve business objectives, improve brand awareness, and build customer loyalty. Technology management: Evaluating, implementing, and managing the marketing technology stack (e.g., CRM, marketing automation platforms, CMS) and ensuring the team can effectively use these tools. Process optimization: Designing, streamlining, and refining marketing processes to improve productivity, efficiency, and cross-team collaboration. Budget management: Developing, managing, and monitoring the marketing budget, including tracking budget vs forecast, and providing financial reports to management in partnership with Finance. Data analysis and reporting: Working with Analytics to analyze marketing campaign performance data, generating reports for stakeholders, and providing data-driven insights and recommendations for improvement. Collaboration: Acting as a liaison between marketing and other departments to ensure alignment on goals and efforts. Building rapport with the Chief of Staff community and working with on cross-company initiatives and planning. Team support: Training and supporting marketing staff, and providing internal support and training on marketing platforms. Experience: 7+ years of experience in operations or
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