Application Security Head in Toronto

About the Role: As a Staff Software Engineer on the ML Infrastructure team, you will collaborate closely with the Machine Learning and Product teams to build world-class machine learning inference platforms. These platforms power essential services like personalized recommendations, search, and content understanding across Tubi. A core responsibility of this team is developing and maintaining low-latency ML model serving systems that support Deep Learning, LLM, and Search models. This involves building self-service infrastructure and critical components such as the inference engine, feature store, vector store, and experimentation engine. You will improve the way we deploy and operate our services and even contribute to open-source projects. This role grants the architectural freedom to explore new frameworks, lead critical cross-functional projects, and transform the capabilities of our ML and Product teams. Responsibilities: Design and build scalable, high throughput, and low latency distributed systems using Scala Build reusable components and services that serve various ML applications like Personalization, Search, Ads and Exploration Partner closely with ML engineers to understand their challenges and limitations and develop scalable solutions to address them. Proactively recommend solutions to keep our ML Inference stack state of the art. Take a data driven approach to identifying & optimizing latency, cost, and efficiency of our infra. Lead large scale cross functional refactorings if necessary Mentor other engineers on the team on system design, effective incident management, interviewing, leveraging LLMs for work, etc. Collaborate with ML, Product, and cross functional engineering teams to define the long term vision and architecture for ML Infrastructure at Tubi. Your Background: Experience designing and building scalable, distributed systems in any modern backend language (e.g., Scala, Java, Python, Go, C++); experience with Scala or JVM 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. Our Infrastructure team is passionate about building software to solve problems at massive scale. We do this often, and when we believe our solution is worth sharing with the community, such as Envoy Proxy , we open source our ideas for the benefit of others. As a Infrastructure Engineer at Lyft, you will run our Production Infrastructure by monitoring system availability and take a holistic view of our platform health. You will build software and platforms to automate infrastructure platform operations and management. By measuring and monitoring our operations you will seek opportunities to optimize our systems in order to push our platform forward, anticipating our customers' needs in order to continually improve the platform. You will provide Lyft partner teams with operational support to help them build robust large scale distributed systems. About the Team Data Pipelines is at the heart of all critical data flowing through Lyft supporting hundreds of services that impact millions of drivers and passengers every day. Our team’s mission is to empower Lyft engineers to self-serve in building and maintaining data pipelines as needed to support products that deliver the world’s best transportation experience. We leverage a variety of technologies to store, stream and manage data making it available to our internal customers. Responsibilities: Maintain and analyze metrics from; operating systems; control planes; and applications to assist in fault detection and performance enhancement Design, develop and deploy tooling and systems that continually improve the reliability, scalability and efficiency of our platform Balance feature development speed and reliability with service-level objectives Operate and improve our Infrastructure using industry best practices and tools Participate in design and

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

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 empowers us to iterate quickly, while focusing on delighting our passengers and drivers. The Applied AI team is looking for a senior software Engineer to join the Recommendations team. You will build the backend systems that decide what we surface to riders. You will architect the pipelines and services that turn rider context and signals into the right offer at the right moment, driving a measurable impact on rider experience. Responsibilities: Establish engineering best practices and patterns; help uplift the team's craft and drive a culture of engineering excellence Drive high-impact projects and innovate new solutions to deliver the best user experience Produce and drive scalable system design for large, complex features — from idea through execution and launch Mentor engineers on the team, providing technical guidance and supporting their growth Champion and evangelize the use of AI tools to accelerate engineering productivity across the team, sharing patterns and best practices that raise the bar for how the team builds Write well-crafted, well-tested, readable, maintainable code Participate in code reviews to ensure code quality and share knowledge across the team Participate in the team's on-call rotation; identify, triage, debug, and resolve issues across our applications and platforms Excellent communication skills and the ability to explain the various trade offs made in decisions Manage project priorities, deadlines, and deliverables. Experience: BS/MS or

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. About the role: You will join a small, highly autonomous cross-functional team to build AI agents that fundamentally transform how operations work at scale. Instead of writing bespoke software for every workflow, we are developing an agent platform that can read operational knowledge, reason about it in context, and execute tasks end-to-end. This approach allows us to scale complexity through knowledge and reasoning, rather than simply through code. This is an opportunity to join a foundational team, which currently consists of fewer than five engineers. The work spans critical areas including LLM-powered agent design, robust backend service architecture, tool and integration development, and sophisticated knowledge infrastructure. We are seeking a Senior Software Engineer with a strong pas

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 Robinhood Wallet team’s mission is to democratize access to financial services worldwide by leveraging DeFi protocols and Robinhood Chain! We build secure, intuitive, and decentralized products that enable our users to custody and manage their digital assets. Our team works at the intersection of traditional finance and web3, driving progress in cryptocurrency and blockchain applications. We work closely across multiple engineering and design areas to deliver highly reliable, high-performance systems for customers worldwide. As a Software Developer , you will build and own the backend services, infrastructure, and data systems that support Robinhood Wallet products. You will develop new features and system enhancements to deliver a highly secure and efficient trading experience for cryptocurrencies and tokenized stocks, including perpetual futures, to customers worldwide. In this role, you will design scalable architectures and maintain high-quality codebases. You will also collaborate with other engineering teams to guide key technical decisions and raise our team's engineering standards. This role is based in our Toronto, ON office(s), with in-person attendance e

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 Robinhood Wallet team’s mission is to democratize access to financial services worldwide by leveraging DeFi protocols and Robinhood Chain! We build secure, intuitive, and decentralized products that enable our users to custody and manage their digital assets. Our team works at the intersection of traditional finance and web3, driving progress in cryptocurrency and blockchain applications. We work closely with product managers, product designers, and backend engineers to deliver highly reliable, high-performance systems for customers worldwide. We pride ourselves on a culture of shared learning, high technical standards, and respectful collaboration. As a Senior Android Developer , you’ll build and own new product features for the Robinhood Wallet Android app. You will develop reliable and secure solutions to deliver a high-quality trading experience for cryptocurrencies and tokenized stocks, including perpetual futures, to customers worldwide. In this role, you will take lead responsibility for designing scalable mobile architectures, defining code standards, and maintaining high-quality codebases. You will collaborate closely with client engineers, backend develop

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 Applied AI team is looking for a Backend Engineer to join the AI Entries team. You will build the foundational infrastructure that connects Lyft to emerging AI ecosystems and devices and architect the APIs and orchestration layers that allow third-party agents and multimodal interfaces to interact with Lyft. By building these robust integration, you will help make Lyft available where our riders are. Responsibilities: Establish engineering best practices and patterns; help uplift the team's craft and drive a culture of engineering excellence Drive high-impact projects and innovate new solutions to deliver the best user experience Produce and drive scalable system design for large, complex features — from idea through execution and launch Mentor engineers on the team, providing technical guidance and supporting their growth Write well-crafted, well-tested, readable, maintainable code Participate in code reviews to ensure code quality and share knowledge across the team Participate in the team's on-call rotation; identify, triage, debug, and resolve issues across our applications and platforms Have the ability to explain the various trade offs made in decisions Manage project priorities, deadlines, and deliverables. Experience: BS/MS or equivalent in Computer Engineering, Computer Science, or related field or equivalent practical experience. 5+ years of software engineering/production

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. Machine Learning is at the heart of Lyft’s products and decision-making. Machine Learning Engineers at Lyft operate in dynamic environments, moving quickly to build the world’s best transportation solutions. We tackle a wide range of challenges, from pricing and marketplace frameworks that ensure reliability and competitiveness, to agentic AI platforms that automate analytical workflows, to behavioral detection systems that protect the integrity of our network. We operate at the intersection of applied ML and real business impact, shipping models that directly influence revenue, rider experience, and partner trust. Lyft Business builds products that help organizations move the people who matter most—employees, customers, patients, and guests—easily and efficiently. Our offerings include Business Travel, Lyft Pass, and Concierge (for healthcare and non-healthcare rides), enabling companies to manage transportation at scale through APIs, integrations (e.g., Concur, Expensify), and dedicated tools. These platforms power high-impact B2B use cases across corporate travel, healthcare access, customer experience, and community programs. We're looking for a Machine Learning Engineer to design, build, and deploy ML systems across Lyft Business. This is a high-scope role: you won't be siloed into one problem area. Instead, you'll move across pricing algorithms, fraud and behavior detection, agentic AI systems, and emerging ML applications as the business evolves. You'll write production-quality code, own models end-to-end from prototyping through deployment, and collaborate closely with Data Scientists, Product Managers, and Software Engineers to translate complex business problems into scalable ML solutions. This role is ideal for someone who is technically versatile, energized by variety, and wants to see th

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 Frontend Software Engineer on the Operator Core Tooling pod, you'll play a vital role in building the robust services that power our critical operations tooling platform. Your work will directly empower our micromobility operations teams by providing them with intuitive and efficient tools, significantly improving their daily workflows as they manage our fleet. You'll collaborate closely with business leaders, front-end developers, and data scientists across Lyft to achieve this impact. Responsibilities: Help define the roadmap and architecture based on technology and business needs 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 See the direct impact of your work on the efficiency of our operating teams Experience: 3+ years of software engineering industry Advanced knowledge of JavaScript Experience working with modern JavaScript frameworks, like React Experience working with NodeJS and Express applications Experience working with design systems (e.g. Bootstrap, Salesforce Lightning, GitHub Primer) Good understanding of web performance and how browsers and DOM work Experience with unit, integration, and end-to-end testing Experience designing, building and improving a set of team owned components Culture of investigating and solvin

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. We are building and maintaining a highly scalable asynchronous platform that empowers our organization to handle critical business cases. As a software engineering team, our mission is to create robust and innovative solutions that drive the success of our business and deliver unparalleled value to our customers. We adopt Infrastructure as Code practice to automate the provisioning and configuration of our resources, which helps reduce manual configuration and improve consistency. Our team culture is built on collaboration, open communication, and a supportive environment where each member's ideas are valued and contributions are recognized. We believe in the importance of fostering a positive workplace culture that inspires innovation and creativity. Responsibilities: Maintain and analyze metrics from; operating systems; control planes; and applications to assist in fault detection and performance enhancement Design, develop and deploy tooling and systems that continually improve the reliability, scalability and efficiency of our platform Balance feature development speed and reliability with service-level objectives Operate and improve our Infrastructure using industry best practices and tools Participate in design and production readiness reviews, platform management and capacity planning ceremonies with cross-functional teams Document Infrastructure operations process and insights, identify repeatable actions and ruthlessly automate repetitive tasks Participate in our teams on-call rotations, respond to incidents and support other teams mitigate customer impacting events Experience: 5+ years experience working on teams responsible for software development, automation and systems engineering Experience building large-scale infrastructure, distributed systems or networks. Knowledge with SQS,