Senior Backend Engineer

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.

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.

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.

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 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.

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.

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.

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.

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.

About CanalsCanals is a thriving remote startup that is revolutionizing the industrial supply chain, a $10 trillion industry, through innovative AI solutions. Our platform integrates effortlessly with the existing systems used by distributors, streamlining cumbersome tasks and minimizing risks in the global movement of physical goods.Our diverse 70-member team, with approximately 45 engineers, is spread across North and South America.The OpportunityAs our customer base grows rapidly, we are looking for senior-level engineers who can act swiftly while ensuring top-notch quality. You will take ownership of intricate backend systems and contribute to the development of product features that provide substantial value to our clients.What You’ll DoFocus on backend engineering with an emphasis on scalability, performance, and reliability.Take charge of large-scale, complex projects from conception to deployment.Work closely with product and customer teams to ensure engineering aligns with business objectives.Balance direct coding tasks with mentorship and technical guidance for the team.Play a pivotal role in shaping the future of Canals as we scale alongside our customers.What We’re Looking ForProven senior-level experience in backend engineering, focusing on scalable, high-performance systems.Experience in a fast-paced, product-driven environment with the ability to work independently.A strong sense of ownership over deliverables, ensuring high-quality project completions.Capability to provide guidance and unblock other engineers through constructive code reviews and architectural insights.Experience in high-growth startups or small teams is highly desirable.Why Join CanalsProfitability: Enjoy the stability that comes without the uncertainty of venture capital pivots.Real Impact: Your contributions will enhance global supply chains, saving time and reducing waste for our customers.Engineering Excellence: We prioritize quality and documentation, fostering sustainable rapid growth.Ownership Culture: We empower our team to move quickly and take initiative.

About MagicalMagical is an innovative automation platform that integrates cutting-edge AI technology into the healthcare sector, providing AI agents capable of functioning effectively in real-world settings.Our mission is to create 'AI employees' that streamline tedious and time-consuming processes, specifically in healthcare—a massive $4 trillion industry laden with administrative burdens. We focus on automating critical tasks such as claims processing, prior authorizations, and eligibility checks, allowing healthcare professionals to dedicate more time to patient care.Our AchievementsAs pioneers in the transition to agentic automation in healthcare, we have achieved significant traction:Dramatic revenue growth with clients expanding into new workflows ahead of contract renewals.Rapid proof-of-concepts completed in just 7 days, delivering tangible value in an industry where similar timelines typically span months.Self-repairing automations with production-level reliability at scale, outperforming competitors who struggle to launch functional solutions.Unlike many AI firms that make grand promises, we provide dependable solutions that yield measurable outcomes. Our backing includes notable investors such as Greylock, Coatue, and Lightspeed, with a total funding of $41M. Our founder, Harpaul Sambhi, is a seasoned entrepreneur who previously sold his first company to LinkedIn.Role OverviewIn your role as a Senior Backend Engineer on the Agent Platform team, you will develop the core systems that drive our AI agents—covering aspects from orchestration and state management to model integration and evaluation pipelines. This position is centered around platform engineering, focusing on building the infrastructure that empowers our team to deliver reliable, production-grade agentic automation.You will work at the forefront of multi-agent systems, designing collaborative strategies for agents to tackle complex healthcare workflows. You will take ownership of essential backend services, overseeing them from architecture to deployment while developing verification systems that ensure our agents perform accurately every time.This hybrid position requires you to be onsite in our Toronto office two days each week.

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.

At Movable Ink, we specialize in taking content personalization to the next level for marketers, utilizing data-driven content generation and AI decisioning. Our innovative solutions are trusted by some of the world's leading brands to enhance revenue, streamline workflows, and increase marketing agility. With our headquarters in New York City and a talented team of nearly 600 professionals, we proudly serve clients across North America, Central America, Europe, Australia, and Japan.As a member of our Analytics team, you will play a pivotal role in measurement, attribution, and the development of an intuitive reporting interface for our digital marketing platform. This is a rare opportunity to influence how marketers perceive and engage with data—turning raw metrics into actionable insights that drive impactful campaigns and deliver tangible business outcomes. Join us to make a significant contribution to a rapidly growing team, take command of innovative projects, and collaborate with cross-functional partners to create a product that marketing teams depend on daily.

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.

About the Opportunity:Join our dynamic team at Tubi TV as a Senior Software Engineer with a focus on Rust. In this pivotal role, you will spearhead the advancement of our backend platform and its associated tooling. Your expertise will be crucial in developing and maintaining key Rust-based infrastructures that will propel Tubi into its next growth phase.You will design and implement high-performance, secure, and scalable systems while collaborating extensively with teams dedicated to compliance, privacy, experimentation, and infrastructure. This position demands a self-motivated individual who can work independently across system domains and mentor fellow engineers while shaping our technical strategy.We are particularly keen on candidates who are eager to integrate AI-driven coding tools (such as Claude Code, Cursor) into their workflow to enhance productivity and code quality. Previous experience with these tools is advantageous.

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.

NimbleRx is a pioneering healthtech company dedicated to transforming the way individuals access, understand, and manage their healthcare. Our journey begins with the ambition to create the world's most beloved pharmacy business. As a rapidly expanding, tech-centric startup, we are committed to enhancing the experiences of both patients and pharmacists. At Nimble, we cultivate a collaborative culture that encourages open communication and purposeful action, empowering us to tackle today's most exciting challenges and achieve rapid growth.* Please note: Sponsorship options are limited as Nimble does not have an entity established in Canada.As a Senior Backend Engineer, you will play a crucial role in designing the technology and customer experiences that are essential to our various web products serving patients, pharmacies, and other clients of NimbleRx (www.nimblerx.com). You will collaborate with a team of exceptional and driven software engineers who prioritize performance, reliability, and scalability in their work. Your contributions will involve close cooperation with other developers, product management, and design teams to define feature requirements and technical use cases, ensuring timely delivery of high-quality code.Our engineering culture: We embrace a philosophy of shared trust and humility, fostering a sense of unity as we collaboratively navigate the challenges of a fast-growing business. Our daily operations reflect our core values of empathy, simplicity, autonomy, leadership, ownership, curiosity, a bias for action, and mentorship, all within a highly cooperative environment.

About FeatheryFeathery revolutionizes data intake workflows for insurance and wealth management firms. Industry leaders depend on Feathery to streamline crucial operations such as underwriting, client onboarding, and automated account openings.With significant revenue growth and increasing demand from enterprises, we are expanding our engineering team to handle progressively intricate, data-driven workflows across our platform.Why We’re HiringAs Feathery continues to grow, so does the complexity and scale of the systems that support our product—ranging from document processing pipelines to real-time workflow execution.We are seeking a Senior Backend Engineer to assist in constructing and scaling the foundational infrastructure behind our document intelligence and workflow platform. This role is perfect for someone who enjoys designing reliable, high-performance systems and taking charge of backend architecture in a rapidly growing B2B SaaS environment.You will collaborate closely with product, engineering, and customer-facing teams to deliver systems that are swift, resilient, and finely tuned to customer requirements.About the RoleThis is a high-ownership role that encompasses:Backend system design and distributed architectureInfrastructure, scalability, and performance optimizationProduct-focused engineering and problem-solvingCross-functional collaboration across product and customer teamsYou will play a pivotal role in shaping the systems that drive Feathery’s platform—ensuring they are reliable, scalable, and capable of managing complex, real-world applications.What You’ll DoBackend Systems & InfrastructureDesign, build, and scale backend services that facilitate document processing and workflow automationDevelop asynchronous pipelines and distributed systems for managing large data volumesConstruct and maintain infrastructure utilizing AWS services and queuing systems (e.g., SQS)Guarantee high availability, fault tolerance, and observability across systemsOptimize systems for performance, scalability, and cost-efficiencyData Processing & Platform CapabilitiesEstablish systems for processing and transforming both structured and unstructured dataIntegrate data sources and ensure seamless data flow