Senior Ai Research Engineer in Toronto

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

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! About the Role Are you passionate about secure-by-design software engineering? Do you want to be at the forefront of AI innovation and enterprise security? Cohere's North team is seeking a Software Engineer with a focus on security to join our mission and make a significant impact. This isn't a review-and-advise role, you'll own and ship production security features that customers rely on every day. Your Role: As a Senior Software Engineer with a security focus, you'll play a pivotal role in building and securing North's architecture. Your responsibilities will include: Software Development: Contributing to the core development of security features such as OIDC/OAuth flows and session management, ensuring North's AI agents are secure Secure Coding: Writing secure code to handle OIDC tokens, user claims, and sensitive data, adhering to best practices for JWT validation and encryption Authentication and Data Protection: Implementing authentication mechanisms including user login, token management, and authorization checks to maintain data integrity Tool Integration: Pulling in new tools to enhance North's security capabilities Dev

Upwork Inc.’s (Nasdaq: UPWK) family of companies connects businesses with global, AI-enabled talent across every contingent work type including freelance, fractional, and payrolled. This portfolio includes the Upwork Marketplace, which connects businesses with on-demand access to highly skilled talent across the globe, and Lifted, which provides a purpose-built solution for enterprise organizations to source, contract, manage, and pay talent across the full spectrum of contingent work. From Fortune 100 enterprises to entrepreneurs, businesses rely on Upwork Inc. to find and hire expert talent, leverage AI-powered work solutions, and drive business transformation. With access to professionals spanning more than 10,000 skills across AI & machine learning, software development, sales & marketing, customer support, finance & accounting, and more, the Upwork family of companies enables businesses of all sizes to scale, innovate, and transform their workforces for the age of AI and beyond. Since its founding, Upwork Inc. has facilitated more than $30 billion in total transactions and services as it fulfills its purpose to create opportunity in every era of work. Learn more about the Upwork Marketplace at Upwork.com and follow us on LinkedIn, Facebook, Instagram, TikTok, and X; and learn more about Lifted at Go-Lifted and follow on LinkedIn. Lifecycle Marketing is a horizontal team that shapes how we engage clients and talent across the full journey, and this role sits in our demand-side acquisition lane. We’re hiring a Lifecycle Marketing Lead, Growth & Acquisition to own high-impact lifecycle programs that help close the new-client acquisition gap through smarter demand capture and stronger engagement with SMB audiences. You’ll lead key initiatives across outbound prospecting and always-on content, translate performance signals into clear recommendations, and help shape how lifecycle marketing contributes to Upwork’s 2026 priorities. This is a senior indi

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! About the Role Are you passionate about secure-by-design software engineering? Do you want to be at the forefront of AI innovation and enterprise security? Cohere's North team is seeking a Software Engineer with a focus on security to join our mission and make a significant impact. This isn't a review-and-advise role, you'll own and ship production security features that customers rely on every day. Your Role: As a Senior Software Engineer with a security focus, you'll play a pivotal role in building and securing North's architecture. Your responsibilities will include: Software Development: Contributing to the core development of security features such as OIDC/OAuth flows and session management, ensuring North's AI agents are secure Secure Coding: Writing secure code to handle OIDC tokens, user claims, and sensitive data, adhering to best practices for JWT validation and encryption Authentication and Data Protection: Implementing authentication mechanisms including user login, token management, and authorization checks to maintain data integrity Tool Integration: Pulling in new tools to enhance North's security capabilities Dev

Join us in building the future of finance. Our mission is to democratize finance for all. An estimated $124 trillion of assets will be inherited by younger generations in the next two decades. The largest transfer of wealth in human history. If you’re ready to be at the epicenter of this historic cultural and financial shift, keep reading. About the team + role We are building an elite team, applying frontier technologies to the world's biggest financial problems. We're looking for bold thinkers. Sharp problem-solvers. Builders who are wired to make an impact. Robinhood isn't a place for complacency, it's where ambitious people do the best work of their careers. We're a high-performing, fast-moving team with ethics at the center of everything we do. Expectations are high, and so are the rewards. The Software Platform team accelerates developer velocity and increases system reliability by building the foundational platforms and tools that power Robinhood engineering. Within this group, the Kubernetes Compute team focuses on building and operating a highly available, scalable Kubernetes-powered container platform. We ensure that our infrastructure seamlessly supports reliable application deployments, integrates core platform capabilities, and enables multi-region scalability. We are expanding our core container systems to support our next phase of technical growth! As a Software Developer, you will focus on building, maintaining, and scaling our container provisioning platforms. Working alongside senior engineers, you will write code to improve our infrastructure capabilities and actively participate in our technical transition to Amazon EKS. In this role, you will collaborate with teams across the organization to ensure robust platform integrations for everyday application needs like security and networking. Your efforts will directly improve system visibility, automation, and reliability across the platform. This role is based in our Toronto office(s), with in-perso

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 vision of the Safety & Customer Care (SCC) team is to foster long-term loyalty to Lyft with every support interaction. If we are successful, a Lyft customer will rarely interact with Lyft Support. But when that interaction occurs, their issue is resolved quickly, effectively, and with true care. For a Lyft customer, their experience of Support should be that “Lyft cares about me and made the experience easy.” As a Data Analytics Lead, you’ll partner directly with cross-functional stakeholders to identify opportunities and design solutions for improving our customers’ support experience. You’ll leverage your analytical expertise to deliver actionable insights and recommendations to drive quality business decisions with customer-facing impact. The ideal candidate is a critical thinker and exceptional problem solver who can build strong relationships with different teams, and who is eager to serve as a leader within the broader Support organization to drive our business forward. Responsibilities Partner with Product, Engineering, Data Science & Analytics, Business Operations and other cross-functional stakeholders to achieve business goals Develop frameworks and scalable processes to drive decision-making and prioritization Define the metrics used to measure the success of strategic initiatives and health of our support platform; build dashboards to track metrics over time Design A/B tests and execute analyses to evaluate the impact of new product features and operational improvements Work closely with cross-functional partners to deliver data-driven insights and actionable recommendations for continuously improving the customer support experience Monitor and diagnose KPI performance and present findings to senior leadership Experience Degree in a quantitative field like statisti

About Sentry Software runs the world and the pace is faster than ever. Sentry helps developers fix errors and performance issues before users notice, so teams can spend less time firefighting and more time building. Trusted by 200,000+ organizations, Sentry is today’s application monitoring standard and our team is building its AI-native future. About the Role At Sentry, Support is an engineering discipline. Our customers are the greatest technical minds in the world—developers at elite enterprises building the future of software—and they deserve answers that go deeper than a knowledge base link. We are architecting the Technical Support engine . We’re looking for a veteran engineer to help us redefine the standard of technical support by combining deep human expertise with autonomous agentic systems. You are a debugger of both code and systems. You will treat support volume as a data signal to build automated resolution paths, ensuring our human engineers only touch the most complex, high-impact architectural puzzles. Sentry Support Engineers aren't just clearing queues; they are Orchestrators . You will engage with our users across GitHub, Discord, and our internal systems, while acting as the Technical Lead for our Agentic Ops. You ensure that when a developer asks a complex question, our systems have the right context and a seamless "Human-in-the-Loop" path to you when deep, nuanced expertise is required. In this role you will Master the Sentry Ecosystem & Support Elite Developers Deep-Dive Debugging: Perform root-cause analysis on complex issues and distributed tracing gaps across polyglot environments. Support the Great Minds: Act as a strategic consultant for senior engineers at our largest enterprise customers, solving high-stakes architectural challenges that push the boundaries of observability. Troubleshoot SDK Implementations: Go deep into the source code of Sentry’s SDKs to help developers instrument complex frameworks and custom environments. Engin

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. Trust and confidence is fundamental to the Lyft marketplace, and the Pay, Integrity & Identity (PII) Analytics team is charged with providing and ensuring that trust and safety to all customers. The PII Analytics team is one of the most critical teams that helps protect Lyft and enables the company to grow in a sustainable way. The team is fast-paced, high-energy, and meticulous in diagnosing emerging fraud patterns and preventing fraud loss before it can happen. We drill holes in all the products we launch and obsess over how to make our business impervious to fraud vectors. The team conducts a rigorous analysis of complex data sets and sets up multiple layers of business rules, models, and other processes to prevent potential fraud. We are a highly cross-functional team and regularly engage in discussion and reviews with stakeholders to prioritize plans for reducing fraud impact and introducing safety features. We’re looking for a rock-star to join a fast-paced environment to contribute to Fraud-related analysis and operations. This individual is responsible for investigating and developing solutions to prevent and mitigate third party fraud. This person will proactively identify fraud patterns and sources to minimize the company’s exposure to financial and reputational risk. The Senior Analyst will take ownership over multiple discrete fraud segments to develop and execute a strategy which addresses fraud in the earliest stages of detection. The Senior Analyst will define fraud prevention measures that are mindful of the impact on good user experience while inhibiting fraud actors’ ability to reach our platform. This person is quantitatively driven, detail-focused, and operations-savvy while ensuring the best possible customer experience. This individual possesses a high level of subject matte

Who We Are At Justworks, you’ll enjoy a welcoming and casual environment, great benefits, wellness program offerings, company retreats, and the ability to interact with and learn from leaders in the startup community. We work hard and care about our most prized asset - our people. We’re helping businesses get off the ground by enabling them to focus on running their business. We solve HR issues. We’re data-driven and never stop iterating. If you’d like to work in a supportive, entrepreneurial environment, are interested in building something meaningful and having fun while doing it, we’d love to hear from you. We're united by shared goals and shared motivations at Justworks. These are best summed up in our company values, which are reflected in our product and in our team. Our Values If this sounds like you, you’ll fit right in. Who You Are You are self-driven and like to work with others to remove roadblocks. You are curious, and love to explore and learn new technologies. You have demonstrated the ability to build, deploy and maintain large-scale, complex applications. You care more about solutions and impacting the customer experience than using a particular tool or framework. Your Success Profile What You Will Work On As a part of the Workforce Management team, you will drive our expansion into exciting new verticals, enriching our platform to attract and delight new customer segments. Your mission will be to architect and deliver foundational solutions in the Applicant Tracking Systems (ATS), Contractor, and Expenses domains. Our specialized product pods focus on building lean, high-impact features for customers who want a streamlined experience without the overhead of a bloated platform. You'll join the expenses pod in Toronto and help build the platform that handles expense submissions, approvals, and reimbursements for Justworks customers. Working alongside 3-4 senior engineers, you'll contribute to our migration from Ruby to Go, build AI-powered features, a

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

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

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 Specialist, Product Management – Attributes & Insights Our Purpose: We work to connect and power an inclusive, digital economy that benefits everyone, everywhere by making transactions safe, simple, smart, and accessible. Using secure data and networks, partnerships and passion, our innovations and solutions help individuals, financial institutions, governments, and businesses realize their greatest potential. Our decency quotient, or DQ, drives our culture and everything we do inside and outside of our company. We cultivate a culture of inclusion (https://www.mastercard.us/en-us/vision/who-we-are/diversity-inclusion.html) for all employees that respects their individual strengths, views, and experiences. We believe that our differences enable us to be a better team – one that makes better decisions, drives innovation, and delivers better business results. About the Team Mastercard Identity, within the Security Solutions organization, leads the development of products and services that enable global commerce, powers financial inclusion, prevents crime and makes some of the most seamless experiences possible. As part of Mastercard Identity, the Attributes & Insights team drives the development and management of products, programs, and services focused on deterministic attribute ve

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 Specialist, Attribute Verification Product Management Our Purpose: We work to connect and power an inclusive, digital economy that benefits everyone, everywhere by making transactions safe, simple, smart, and accessible. Using secure data and networks, partnerships and passion, our innovations and solutions help individuals, financial institutions, governments, and businesses realize their greatest potential. Our decency quotient, or DQ, drives our culture and everything we do inside and outside of our company. We cultivate a culture of inclusion (https://www.mastercard.us/en-us/vision/who-we-are/diversity-inclusion.html) for all employees that respects their individual strengths, views, and experiences. We believe that our differences enable us to be a better team – one that makes better decisions, drives innovation, and delivers better business results. About the position Services within Mastercard is responsible for acquiring, engaging, and retaining customers by managing fraud and risk, enhancing cybersecurity, and improving the digital payments experience. We provide value-added services and leverage expertise, data-driven insights, and execution. Mastercard Identity, within the Security Solutions organization, leads the development of products and services that enable global comme

Level Up Your Career with Zynga! At Zynga, we bring people together through the power of play. As a global leader in interactive entertainment and a proud label of Take-Two Interactive, our games have been downloaded over 6 billion times—connecting players in 175+ countries through fun, strategy, and a little friendly competition. From thrilling casino spins to epic strategy battles, mind-bending puzzles, and social word challenges, our diverse game portfolio has something for everyone. Fan-favorites and latest hits include FarmVille™, Words With Friends™, Zynga Poker™, Game of Thrones Slots Casino™, Wizard of Oz Slots™, Hit it Rich! Slots™, Wonka Slots™, Top Eleven™, Toon Blast™, Empires & Puzzles™, Merge Dragons!™, CSR Racing™, Harry Potter: Puzzles & Spells™, Match Factory™, and Color Block Jam™—plus many more! Founded in 2007 and headquartered in California, our teams span North America, Europe, and Asia, working together to craft unforgettable gaming experiences. Whether you're spinning, strategizing, matching, or competing, Zynga is where fun meets innovation—and where you can take your career to the next level. Join us and be part of the play! Position Overview We are seeking a Senior Product Manager with experience in Ad monetization or Ad Technology systems to shape, execute & distribute our Ad Technology SDK across 50+ Games at Zynga! This role specializes in key aspects of our product lifecycle, building customized ad formats for our games and delivering experiments, readouts and optimizations. This role requires a blend of product management and ad monetization experience. Ideal candidates should have experience working on monetization/payments systems and should be deeply familiar with how games balance engagement with IAA/IAP monetization. What You'll Do Lead experiments for our Advertising platform from experiment design through analysis and rollout -> fine-tuning supply and demand side features that impact how our players see ads