Senior Software Engineer - Authentication Experience

Zip Co Limited is looking for Backend Software Engineers in Toronto to join the team responsible for building and maintaining the backend systems behind financial services products. Candidates at any stage of their engineering career are welcome to apply. Role overview This role centers on designing, developing, and supporting scalable backend systems. Collaboration is a key part of the work, with engineers partnering closely to address technical challenges and drive improvements in financial services offerings. What you will do Design, develop, and maintain backend systems that scale Work with teammates to tackle technical problems Contribute to projects that enhance financial services products Requirements Background in backend engineering (open to all experience levels) Interest in building systems that are both reliable and scalable Ability to collaborate effectively with others Drive to solve complex technical problems This position is located in Toronto.

About BreeBree is transforming the consumer finance landscape by providing innovative, efficient, and cost-effective financial services to over half the Canadian population living paycheck to paycheck. Operating within a vast yet underrepresented market, we aim to be the most affordable and reliable provider of short-term credit for the 20 million Canadians facing financial challenges.With over 600,000 Canadians already benefiting from Bree's services, we are just beginning our journey. Our company is experiencing rapid growth, achieving product-market fit, and is positioned to become a leading FinTech player in Canada. With annualized revenues in the eight-figure range, we are on a double-digit growth trajectory, maintaining profitability and an impressive employee retention rate. As a proud participant of Y Combinator in 2021, we successfully secured a $2 million seed funding shortly thereafter.About the RoleWe are seeking a talented Backend Software Engineer to lead the architectural development of our serverless infrastructure, utilizing the latest AI development tools. The ideal candidate will possess extensive backend experience, a dedication to creating clean and maintainable systems, and an innovative mindset towards AI-assisted development.What You'll DoArchitect and advance our serverless backend systems with an emphasis on scalability, maintainability, and enhancing the developer experience.Refactor and modernize our existing Lambda-based microservices architecture to implement patterns that optimize AI tool effectiveness.Create and maintain robust data pipelines and payment processing systems across various providers.Promote best practices in AI-native development, establishing patterns and abstractions that foster rapid iteration with tools such as Cursor and Claude Code.Collaborate with infrastructure engineers to refine our AWS-based architecture using Infrastructure as Code.Drive the consolidation and standardization of our data layer across Supabase, Firebase, and legacy systems.What You'll NeedExpert-level proficiency in TypeScript, Node.js, and AWS services.Demonstrated experience with serverless architectures and microservices.Strong understanding of database systems and data modeling.Familiarity with AI development tools and methodologies.Excellent problem-solving skills and a proactive approach to development challenges.

Join Us at HarveyAt Harvey, we are revolutionizing the landscape of legal and professional services. Our approach is not merely incremental; we are committed to a comprehensive transformation. By leveraging cutting-edge AI technologies, a robust enterprise platform, and profound expertise in the domain, we are redefining how critical knowledge work is executed for generations to come.This is an exceptional opportunity to contribute to a generational company at a pivotal moment in its growth. With over 1,000 clients across 58 countries, a strong product-market fit, and support from world-class investors, we are experiencing rapid growth and creating a new category in real-time. The challenges are ambitious, the standards are high, and the potential for personal, professional, and financial growth is unparalleled.Our team consists of sharp, motivated individuals who are deeply dedicated to our mission. We operate with urgency, take ownership of our challenges, and are committed to delivering impactful solutions — from initial concepts to long-term results. We maintain close relationships with our customers, from leadership to engineers, collaborating to address real problems with urgency and care. If you thrive in dynamic environments, strive for excellence, and wish to influence the future of work alongside high-achieving peers, we invite you to build with us.At Harvey, we are scripting the future of professional services today, and we are only just beginning.Role SummaryAs a Backend Software Engineer at Harvey, you will be instrumental in building the foundational infrastructure of our product platform, while also developing user-facing features for some of the world's leading law firms and enterprise clients. This team is responsible for the platform layer that ensures secure, reliable, and adaptable experiences for our customers, including notifications, permissions, and feature flag infrastructure. Additionally, we create enterprise-grade collaboration tools tailored for law firms.You will design systems that serve as critical infrastructure for the wider company, directly influencing how our users engage with Harvey's AI-driven legal tools. This position is perfect for engineers eager to oscillate between in-depth platform architecture and hands-on product development.This position is based in Toronto, Canada. We operate on a hybrid model, with a requirement of 3+ days in the office per week, and we offer relocation assistance to new hires.

Join Justworks as a Senior Backend Software Engineer and play a pivotal role in shaping our technology landscape. You will work on high-impact projects, designing and implementing scalable backend systems that support our mission of simplifying business operations for our clients. Your expertise in backend technologies will be critical in delivering exceptional digital experiences.

Join the Revolution at HarveyAt Harvey, we are redefining the landscape of legal and professional services with a bold vision that encompasses an entire ecosystem. By leveraging cutting-edge agentic AI, an enterprise-level platform, and unparalleled domain expertise, we are transforming how essential knowledge work is executed for generations to come.This is an extraordinary opportunity to contribute to a groundbreaking company at a pivotal stage in its journey. With over 1,000 customers spread across more than 58 countries, a strong product-market fit, and exceptional investor backing, we are on an accelerated growth trajectory and are creating a new category in real time. The challenges are ambitious, standards are high, and the potential for personal, professional, and financial growth is unparalleled.Our team is comprised of talented, driven individuals who are deeply committed to our mission. We operate with a sense of urgency and ownership, tackling problems from ideation to execution. We maintain close relationships with our customers, collaborating across all levels to address significant challenges with care and speed. If you thrive in dynamic environments, strive for excellence, and wish to influence the future of work alongside a team that continuously raises the bar, we welcome you to join us in building something remarkable.At Harvey, we’re not just envisioning the future of professional services; we are actively crafting it today.Role OverviewAs a Senior Backend Software Engineer at Harvey, you will be instrumental in laying the groundwork for our product platform while developing user-facing features for some of the world's leading law firms and enterprise clients. Your team will manage the platform layer that ensures secure, reliable, and adaptable experiences, including notifications, permissions, and feature flag infrastructure. You will also create enterprise-grade collaboration tools tailored for law firms.Your responsibilities will include designing and managing systems that serve as the backbone of our operations and significantly influence how users engage with Harvey’s AI-enhanced legal solutions. This role is perfect for engineers who are eager to oscillate between extensive platform architecture and hands-on product development.This position is based in Toronto, Canada, and we operate under an in-person work model, offering relocation assistance to new team members.What You’ll DoDesign and develop robust backend infrastructure, including authentication systems, user permissions, feature flagging, notifications, and document management integrations.Enhance and evolve Harvey’s internal product platform, facilitating development across various product lines and engineering teams.Collaborate with cross-functional teams to identify and address user needs, ensuring a seamless experience.Implement best practices in software development and contribute to a culture of continuous improvement within the engineering team.

Join Centari as a Senior Backend Software Engineer!At Centari, we revolutionize high-stakes dealmaking by unlocking the power of private deal data. Our innovative deal intelligence platform is paving the way for a new era in law and finance, transcending mere automation to embrace data-driven decision-making. Our proprietary Deal Reasoning Engine converts complex documents into actionable insights, equipping global deal teams with the knowledge needed to negotiate effectively.We foster a diverse team of attorneys, financial experts, and engineers within a hybrid, cross-cultural environment. Our mission is supported by esteemed enterprise AI investors, including GTMfund and industry veterans such as Jeremy Kranz and Andy Appelbaum.We thrive on complexity as it breeds innovation. If you're a proactive builder who excels in ambiguous situations and embraces radical ownership, we want to connect with you!For more details, visit centari.com or follow us on LinkedIn.

Role Overview Venn is hiring a Senior Backend Engineer in Toronto. This role focuses on designing and improving backend architecture to support reliable, scalable applications. The position involves close collaboration with colleagues from various teams to deliver solid software that supports business goals.

At Lyft, we are dedicated to connecting and serving our community. Our mission is to foster a workplace where every team member feels a sense of belonging and can thrive in their roles.The Marketplace teams are integral to our products and strategic decisions. We are in search of passionate and motivated engineers to develop systems that empower our users—both Drivers and Riders—by enhancing their experience with Lyft's offerings, making them more predictive, personalized, and adaptive. If you are enthusiastic about tackling challenges in distributed computing, machine learning, and data while building robust systems, we invite you to join our fast-paced, innovative, and collaborative environment.As a Backend Software Engineer, you will leverage your technical skills to manage project timelines, priorities, and deliverables. You will be responsible for designing, developing, testing, deploying, maintaining, and enhancing our platform offerings, significantly impacting various business areas.We seek self-starters with a proven track record of delivering software solutions that address critical business needs. The ideal candidate will dive deep into complex problems and devise technical solutions to resolve them. Ownership of projects or features, driving them from design to execution, is essential.The Growth Platforms team oversees the Incentives & Messaging systems at Lyft, responsible for delivering timely and relevant messaging and incentives to users. Collaborating with cross-functional engineering teams—including those focused on rider and driver experiences, marketing, and product management—you will help adapt our services and platform offerings to support Lyft's growth. You will have the chance to enhance quality and efficiency through machine learning optimizations that impact critical aspects of our platform.

Marqeta is seeking skilled Senior Backend Software Engineers to become part of our dynamic Engineering team. In this role, you will develop high-performance software that supports Marqeta's backend services. Your responsibilities will include creating and reviewing engineering design documentation, enhancing our systems, infrastructure, and processes, developing new features, conducting code reviews, and collaborating with a diverse group of stakeholders across the organization. As a Backend Engineer, you will deliver meaningful products that contribute to Marqeta's position as a leader in modern card issuing. You'll have the opportunity to innovate on system architecture, produce impactful software, and mentor junior engineers. Participation in a rotational on-call pager duty is a required aspect of this role, with specifics varying by team. This will be discussed further during the interview process. We embrace a Flexible First approach, allowing this role to be performed remotely from anywhere within Ontario or British Columbia, Canada. We would love for you to join our team! This posting is for multiple Senior Software Engineering positions across Marqeta.

Join Opendoor as a Software Engineer specializing in Backend Pricing, where you will play a pivotal role in shaping the future of real estate technology.As part of our dynamic team, you will develop innovative back-end solutions that enhance pricing algorithms, ensuring optimal performance and delivering a seamless user experience.

Join our dynamic Data Intelligence team at Achievers, where we develop innovative backend services that transform data from our SaaS platform into actionable insights that drive success for our customers. We are revolutionizing data utilization at Achievers by providing high-impact, intelligent services that redefine workplace efficiency. Our technology stack includes microservices crafted with Python and Go, deployed on Google Cloud Platform (GCP) and Kubernetes. Be a part of a team that aims to create seamless, intelligent, and delightful user experiences while tackling real engineering challenges at scale.

Join our innovative Data Intelligence team as a Senior Software Engineer focused on backend engineering. You will play a crucial role in developing backend services that convert data from our SaaS platform into valuable, actionable insights for our clients. At Achievers, we are revolutionizing data utilization by providing high-impact and intelligent services that redefine workplace efficiency. Our technology stack is built on microservices using Python and Go, deployed on Google Cloud Platform (GCP) and Kubernetes. You will contribute to creating smooth, intelligent, and delightful experiences for our users while tackling real engineering challenges at scale. Note: This is not a Data Engineering position.

Faire’s Search FX team is hiring a Staff Backend Engineer to help shape the Discovery Experience for users. This team builds and refines the backend systems that power search, making it easier for clients and their customers to find what they need on the platform. The work has a direct impact on how people interact with Faire every day. What you will do Design, build, and optimize backend systems that support search features Keep search experiences smooth and reliable for users Collaborate with cross-functional partners to identify technical improvements and areas for innovation Mentor junior engineers and contribute to their professional growth Requirements Solid experience in backend development Background in building scalable systems Comfort working in a quickly changing environment Interest in collaborating with different teams Enjoys supporting others in their engineering careers Location Kitchener-Waterloo, ON or Toronto, ON

Category-defining tech. Career-defining work.At Cockroach Labs, we are not just another tech company; we are pioneers in creating a scalable, cloud-native distributed SQL database. Our mission is to empower innovative companies by providing them with the tools they need to build and expand their applications seamlessly. We embrace challenges head-on and focus on delivering impactful solutions that truly matter.Because when our customers win, we all win.The RoleWe are on the lookout for a passionate backend software engineer to join our KV team, which is dedicated to enhancing our open-source, cloud-native distributed SQL database. This team plays a critical role in developing the foundational elements of CockroachDB, including Resource Management (data sharding, placement, rebalancing), Admission Control, the Transaction Layer (transactional APIs, distributed transactions, and concurrency control), and the Replication Layer (Raft, distributed lease management, and configuration changes). Collectively, these subsystems form the backbone of CockroachDB, enabling its remarkable scalability and resilience.

Join Spotify's dynamic team as a Backend Engineer focused on our Platform. In this role, you will have the opportunity to design, develop, and maintain backend services that support our vast music streaming ecosystem. You'll work alongside talented engineers to deliver high-quality solutions that enhance user experience and drive innovation.

Empower Every Identity, from AI to HumanIdentity is critical in harnessing the potential of AI. At Okta, we secure AI by developing a trusted, neutral infrastructure that allows organizations to confidently navigate this transformative era. This mission demands a relentless commitment to tackle complex, real-world challenges. We seek individuals who build and own their projects, operating with urgency while delivering excellence.This role offers a chance to engage in career-defining work. If you share our passion for this mission, let's connect.The TeamHave you ever pondered how large enterprises ensure that the right individuals access their most crucial systems? That's the core challenge we address.The Okta Privileged Access Management (PAM) team employs an identity-centric methodology to tackle a vital privileged access use case. Our sophisticated Zero Trust architecture is tailored for the modern cloud, aiding customers in resolving significant security and operational challenges on a large scale.Our team constructs the infrastructure that governs access to sensitive servers, databases, and cloud resources, ensuring access is granted only when necessary. We serve as the security layer bridging users (and non-human interfaces) with the systems essential for their tasks. The RoleWe are in search of a Staff Backend Software Engineer passionate about solving complex problems: distributed systems and creating software where precision is paramount. You will deploy code that safeguards real infrastructure for authentic organizations. Your work will underpin multiple feature teams. Enhancements you make in speed, reliability, or usability will have a ripple effect throughout the product.This position is for someone who enjoys contemplating how systems interconnect. You should possess strong viewpoints on effective abstractions and the adaptability to refine these abstractions as the product evolves. What You’ll Be Doing Actively contribute to the evolution of PAM's core architectureCollaborate with product development teams to create scalable, composable components of our platformDesign and implement scalable architecture patternsDevelop APIs utilizing OpenAPI Specification that our customers depend on for production infrastructure accessEngage with backend systems developed in GoParticipate in rotational on-call responsibilities alongside SRE and product teams

About the TeamThe Customer Experience (CX) Product team is responsible for overseeing the entire post-booking journey. This includes managing changes, disruptions, refunds, and customer support interactions from the moment a trip is booked.We develop and maintain high-quality systems that facilitate rapid and efficient customer support on a large scale, such as:Customer self-service experiences within the Hopper app and integrated flows with partners.Internal agent platforms that enable efficient and high-quality resolutions by human agents.HTS Assist, Hopper’s premier AI platform, utilized internally and offered as a B2B solution to global travel partners.Together, these platforms serve millions of travelers through chat, voice, web, and third-party channels, enhancing the post-booking experience globally.About the RoleAs a Senior Software Engineer on the CX Platform team, you will be instrumental in designing, building, and evolving the foundational systems that power Hopper’s post-booking operations. Your contributions will have a direct impact on customer interactions, support agents, and the ongoing growth of HTS Assist in AI-driven voice and chat applications.You will collaborate closely with Product, Design, AI, Data, and Operations teams to create intelligent and scalable customer service systems, including conversational AI workflows, self-service customer journeys, and internal tools utilized by thousands of agents. You will also help develop infrastructure that supports partner-specific experiences.Reporting to a Senior Engineering Manager, you will work alongside engineers focused on platform services, integrations, AI orchestration, and self-service user experience.Day-to-Day ResponsibilitiesDesign, build, and enhance backend and/or full-stack systems that support HTS Assist, internal agent tools, and customer self-service flows.Create scalable APIs, microservices, and orchestration logic that facilitate complex post-booking journeys across AI, chat, voice, and web platforms.Collaborate with product, design, AI, and operations teams to implement features that improve customer experiences and boost agent productivity.Integrate with external systems such as telephony, CRM, identity, or booking platforms to support both internal and partner use cases.Take ownership of features from technical design through implementation, testing, deployment, monitoring, and iteration.

About the Team The Production Scheduling Technology team is at the forefront of automating and optimizing how HelloFresh orchestrates its meal production processes. We have successfully launched a next-generation internal system that automates the entire planning workflow, significantly impacting how millions of meals are distributed throughout our network. As we enhance this system and prepare for future growth, we are seeking a Senior Backend Engineer with robust backend expertise, a knack for transforming intricate logic into effective and dependable systems, and a moderate understanding of full-stack development to support our internal applications. We prioritize candidates who can contribute to our mission at HelloFresh. We value diverse experiences and believe that anyone can excel in this role, so we encourage you to apply even if you don't meet every single requirement. Responsibilities Develop, enhance, and share ownership of a Python-based algorithmic engine that fuels automated planning, incorporating deterministic logic and constraint-based components. Create, develop, and sustain backend services utilizing FastAPI, ensuring scalable and reliable API interactions with our internal applications. Engage in the complete technology lifecycle, including architecture, implementation, deployment, and operations within our advanced tech stack (EKS, RDS, S3, ElastiCache, Glue, etc.). Collaborate with engineers, analysts, and planners to translate domain insights into robust and maintainable system logic. Advance the platform towards an event-driven architecture using technologies such as Kafka. Assist with frontend requirements for our internal React application, ensuring seamless integration between frontend and backend systems. Enhance system reliability through automated testing, performance optimization, and thoughtful design principles. Foster a culture of knowledge sharing and collective ownership through pairing, design discussions, and collaborative learning. Contribute to the strategic direction of an innovative system. Qualifications Proven experience in backend development, particularly with Python and FastAPI. Strong understanding of API design and microservices architecture. Experience with event-driven systems and related technologies (e.g., Kafka). Familiarity with cloud services and infrastructure (AWS, EKS, RDS). Ability to work collaboratively in a team-oriented environment. Excellent problem-solving skills and attention to detail. A proactive attitude towards learning and sharing knowledge.

About the Team Okta’s Privileged Access Management (PAM) group builds the infrastructure that controls access to sensitive servers, databases, and cloud resources for large organizations. The team acts as a security barrier, ensuring access is granted only when necessary, whether to people or automated systems. Their work underpins the security of critical systems and supports multiple feature teams across Okta. Role Overview The Backend Software Engineer will focus on designing and building distributed systems where accuracy and reliability are essential. This role involves developing core components that impact the performance, reliability, and usability of the PAM product. Improvements made here ripple out to the entire platform, supporting real-world organizations and their most vital infrastructure. What You Will Do Build and maintain backend systems that manage privileged access to sensitive resources Work on distributed systems challenges, ensuring high reliability and scalability Develop foundational software components used by multiple teams Focus on performance, reliability, and usability improvements Contribute to an identity-centric approach for modern cloud environments Who Thrives Here Engineers who enjoy thinking about how complex systems fit together People with strong opinions on abstraction and a willingness to adapt as products evolve Those who like tackling real-world security and operational challenges at scale Individuals who value precision and care in their code Location This position is based in Toronto, Ontario, Canada.