Senior Full-Stack Software Developer with React.js Expertise

About Stay22At Stay22, we are transforming the way people convert online. Our AI-powered affiliate platform empowers publishers, ticketing platforms, and content creators to unlock new revenue streams while enhancing their audience's user experience. Our partners don’t just earn more; they provide more. Join us in making a significant impact in the world of affiliate marketing.About the PositionAs a Senior Full-Stack Developer on the Phantom team, you will play a pivotal role in developing our integrated widget and affiliate platform. You will optimize browser-side script execution to ensure high performance across various sites, while designing privacy-respecting session tracking and fingerprinting mechanisms. You will oversee the entire script lifecycle, from load optimization to event management and error recovery, contributing to the infrastructure that powers Stay22's embeddable products.Key ResponsibilitiesContinuously optimize load times and script execution efficiency (minification, caching, lazy loading).Develop reliable methods for injecting content and widgets across different sites (DOM, dynamic layouts).Implement precise event handlers to track user interactions with embedded elements.Utilize fingerprinting techniques to track user sessions while ensuring privacy compliance.Create and maintain Node.js/Python scrapers for data collection from partner sites or APIs, with failover sources to ensure resilience.Troubleshoot and adapt script logic for real-world conditions and manage conflicts with third-party scripts.Oversee the entire stack of integrated products (scripts, SDK, API) and collaborate with teams to implement new features.

About Us:At AssistIQ, we are committed to revolutionizing the healthcare supply chain by empowering providers with the ability to generate precise data and insights regarding their supply usage. Our innovative AI-powered software solution ensures seamless tracking, real-time visibility, and actionable insights for healthcare systems, ultimately promoting waste reduction and enhancing revenue capture, leading to improved patient care and outcomes.About the Role:As a Full Stack Software Engineer, you will play a pivotal role in designing, developing, and managing the cloud-based services and web applications that drive the AssistIQ platform.We are looking for candidates who thrive in a fast-paced, entrepreneurial environment. Your primary objective will be to ensure the development of new functionalities in a practical, scalable, and maintainable manner.Success in this role requires the ability to manage multiple responsibilities simultaneously, prioritize competing deliverables effectively, communicate clearly across the organization, and maintain a focus on continuous incremental improvement.We expect you to be knowledgeable, articulate, and sensible, capable of coordinating with peers and senior executives, while collaborating to deliver results in a dynamic environment where teamwork, professionalism, confidentiality, and communication are paramount.Your Responsibilities:Design, develop, and enhance new functionalities of the AssistIQ platformOptimize the deployment process and ensure adherence to automation and continuous integration best practicesSupport the production infrastructure and our product for customersAssist internal customer support and implementation teamsDevelop internal tools to enhance our deployment, management, and monitoring capabilitiesProvide technical and analytical guidance to fellow development team membersContribute to the writing and maintenance of technical documentationEngage in planning product features and development projectsParticipate in our Agile development process and ceremonies

Location: US or CanadaType: US Applicants - Full-Time; Canadian Applicants - Independent ContractorAbout Human AgencyAt Human Agency, we are experiencing rapid growth and are looking for exceptional talent across various disciplines to join our innovative team. Our mission is to attract diverse individuals, from creative producers to technical experts and entrepreneurial leaders, who can help us navigate this exciting chapter of growth.We pride ourselves on being a company of doers. Our leaders are hands-on, teams collaborate openly, and every member contributes to our projects. We welcome feedback, learn swiftly, and continuously strive for excellence. Here, the best ideas prevail, regardless of their origin, as our clients rely on us to deliver outstanding results every time.Our clients’ missions, products, and bottom lines are of utmost importance to us. We immerse ourselves in their vision, acting as partners in tackling significant challenges. Every product, strategy, or asset we develop must be not only aesthetically pleasing but also functional, practical, and designed for real-world impact.We believe that our people are our greatest asset and we grow by hiring those who elevate our capabilities. Across strategy, engineering, design, data, and operations, we seek teammates who inspire us to reach new heights. Always hire up, never down.We collaborate with organizations of all sizes to explore, design, and implement secure, scalable, and human-centered AI strategies. Our conviction is that AI should enhance human potential, not replace it. We build this philosophy into every engagement, from advisory and tooling to implementation and education, meeting clients where they are and helping them integrate AI in ways that align with their mission and values. Our aim is to empower teams to work smarter, move faster, and unlock new possibilities through thoughtful, responsible innovation.Above all, we lead with purpose, love, and a sense of adventure. We engage in meaningful work with people we care about, making the journey an adventure worth undertaking. At Human Agency, our identity and our work approach are one and the same.The OpportunityAs a Senior Full-Stack Engineer at Human Agency, you will be at the forefront of shaping the future by integrating cutting-edge AI solutions with intuitive software development. We specialize in building scalable and secure SaaS applications that empower enterprise clients to efficiently solve complex challenges. Join our team and work on high-impact projects at the intersection of AI, machine learning, and secure software engineering.

About the RoleJoin us at saris-ai, an innovative applied AI startup with offices in San Francisco and Montreal, dedicated to revolutionizing the banking sector. We are addressing a monumental $100 billion annual challenge that grows exponentially each quarter, redefining the limits of multi-turn AI agent systems.Our mission is to solve complex automation issues that demand long-context reasoning, seamless tool integration within legacy systems, and adherence to stringent compliance requirements—problems that often lack straightforward solutions.We have successfully deployed real agents that manage genuine customer workflows, and as our customer base expands and our deployments grow, we are rapidly scaling our operations. We are on the lookout for passionate, technically skilled builders who wish to make a significant impact at an early stage.Our engineering team is in search of a Full Stack Software Engineer with a strong understanding of product and internal processes. You will work closely with our sales and Go-To-Market teams to optimize internal workflows and accelerate the sales cycle.

Hello! Thank you for stopping by Are you actively seeking a new opportunity or just exploring the market? If so, you may be in the right place to join our team.The Financial Automation team at Lightspeed is dedicated to simplifying merchant operations by replacing tedious manual processes, such as sales reconciliation, with intelligent automated systems powered by AI. We bridge the gap between complex data and actionable insights, enabling our users to manage their growth without increasing their workforce.As a Senior Full Stack Developer, you will be responsible for the development and maintenance of various features within our financial products. This role emphasizes frontend development (approximately 70%). You will make significant contributions to the overall codebase by delivering new features, fixing bugs, enhancing user experiences, and supporting related activities. We expect you to possess strong technical expertise to help the team achieve its goals, evolve processes and tools, and actively participate in production operations, including on-call rotations.Note: We only accept applications from residents of Canada.

Join MaintainX, the leading mobile platform for procedure management tailored for industrial workers and frontline personnel. We are building the GitHub for real work procedures such as maintenance, safety, and operations, enhancing operational efficiency for over 12,000 companies including Duracell, Univar Solutions Inc., Titan America, McDonald's, Brenntag, Cintas, Michaels, and Shell. Recently, we secured a Series D funding of $150 million, bringing our total funding to $254 million and valuing the company at $2.5 billion. We are seeking a Full-Stack Developer to join our dynamic teams. Positions are available for intermediate, senior, and lead roles. Your Responsibilities: Collaborate with Product Managers and Designers to conceptualize new features and contribute to product roadmaps. Adopt a product mindset to understand customer activities, needs, and technical opportunities and challenges within their industries. You will work across our entire stack (TypeScript, React, React Native, Node.js, and GraphQL) for both Web and Mobile applications. Work with the team to build, maintain, and optimize product features that enhance user collaboration. Take ownership of features or systems within the team, ensuring their long-term health and the improvement of surrounding systems. Mentor other engineers and conduct thorough code reviews. Enhance engineering standards, tools, and processes, and implement industry-compliant best practices in planning, development, testing, and deployment. Be available on-call. Your Profile: Minimum 3 years of professional experience in full-stack software development, with a background in building web and mobile-based software products, particularly with TypeScript, SQL databases, React, and Node.js. Experience in iterative web development and mobile-first responsive design. Ability to write clear and maintainable code.

Xsolla seeks a Full-Stack Engineer in Montreal to support the development and enhancement of its gaming platform. This position involves working on both front-end and back-end components, with frequent collaboration across various teams. Responsibilities Design, build, and maintain features for both the user-facing and server-side parts of the platform Partner with team members from different departments to implement platform improvements Location This role is located in Montreal.

Hello and welcome! Are you searching for an exciting new opportunity, or just exploring the job market? You may have just found the perfect place to elevate your career by joining our innovative team. The Financial Automation team at Lightspeed is dedicated to simplifying merchant operations by transforming tedious manual tasks, such as sales reconciliation, into intelligent, AI-powered automated solutions. We connect complex data with actionable insights, empowering our users to scale their businesses without the need for additional personnel. As a Senior Full Stack Software Developer, you will play a key role in developing and maintaining essential features for our high-stakes financial products. This position emphasizes frontend development, with approximately 70% of your responsibilities focused on frontend tasks, while the remaining 30% will encompass other aspects of our tech stack. You will contribute significantly to our codebase by delivering new features, resolving bugs, enhancing user experiences, and supporting related initiatives. We expect you to bring a wealth of technical knowledge, assist the team in achieving their objectives, evolve our processes and tools, and actively participate in various operational duties, including on-call support. Please note: We welcome applications exclusively from candidates located in Canada.

Join Medfar as a Senior Full Stack Developer and play a pivotal role in transforming the healthcare SaaS landscape. You will be responsible for designing and implementing innovative software solutions that enhance patient care and streamline healthcare processes. Collaborate with cross-functional teams to deliver high-quality applications that meet the needs of healthcare professionals and patients alike.

About ValPayValPay is an innovative embedded payment solution designed to streamline the onboarding of merchants, facilitate transaction processing, and enhance revenue optimization. Our unique PayFac-as-a-Service model provides all the advantages of integrated payments without the complexities of underwriting, compliance, and regulatory requirements typically associated with being a Payment Facilitator (PayFac).About the RoleWe are seeking a talented Senior Full-Stack Developer with over 5 years of professional experience and a strong enthusiasm for application development to join our agile engineering team in a fast-paced startup setting. In this pivotal role, you will play a key part in designing, optimizing, and scaling essential features across our payment systems, engaging in both front-end and back-end development. You will collaborate closely with product, design, and support teams, contribute to architectural decisions, resolve bugs, and produce high-quality production-level code that significantly impacts our clients.Key ResponsibilitiesCreate, develop, and maintain scalable full-stack applications supporting ValPay’s embedded payments platform.Design and enhance APIs, backend services, and frontend interfaces used by SaaS partners and internal stakeholders.Collaborate with Product, Customer Support, and Customer Success teams to transform requirements into effective technical solutions.Integrate third-party services using APIs and payment infrastructure.Contribute to architectural and data strategy as our platform evolves.Identify and resolve performance issues, ensuring system reliability and efficiency.Uphold high standards of security and performance in a regulated payments environment.Participate in code reviews and mentor junior developers.Document technical processes and data flows clearly and thoroughly.Utilize AI tools and workflows to enhance development productivity.Share insights and lessons learned with team members.

JOIN OUR TEAM:At Xsolla, we empower creators with a comprehensive creative suite that enhances their entire content creation experience. Our platform offers monetization and engagement tools, serving as a central hub for creators to earn while promoting publishers’ games. For game publishers, we deliver advanced data reporting and campaign management tools that facilitate data-driven marketing strategies for their latest releases.As a Full Stack Developer, your role will encompass our entire technology stack, from developing dynamic React applications for creators and publishers to managing backend Node.js microservices that process data and power our REST/gRPC APIs. You'll address challenges such as optimizing queries on our extensive creator data database and ensuring our systems can efficiently scale during major game launches.Our team thrives on curiosity, continuous improvement, positive energy, and diverse perspectives. We regularly revisit our decisions to carve out better solutions. We take pride in not just creating exceptional products but also cultivating a company culture that inspires us. Join us to tackle complex problems with a team we deeply respect and enjoy working alongside.

Location: Montreal, Canada (Hybrid) Job Type: 12-month contract Experience Level: 7+ years Work Focus: 70% Frontend (React/TypeScript), 30% Backend (.NET Core) Role Overview dyneits is looking for a Senior Full Stack Developer to help advance Capital Markets applications, including IRIS and CurveBuilder. The position centers on frontend work with React and TypeScript, while also involving backend contributions in C# .NET Core. This hybrid role is based in Montreal and involves close collaboration with trading and IT teams worldwide. Main Responsibilities Frontend Development (Primary) Design and build user interfaces using TypeScript and React. Improve and maintain application interfaces for a strong user experience. Apply advanced frontend techniques such as Promises, Redux, and Callbacks. Implement real-time communication with SignalR. Backend Development (Secondary) Develop backend services with C# .NET Core. Support and enhance IRIS backend systems. Create and maintain APIs and business logic. Application and Performance Improvement Work on application performance and scalability enhancements. Contribute to system modernization and evolution. Maintain code quality and efficiency. DevOps and CI/CD Maintain and improve CI/CD pipelines. Work with AWS, Kubernetes, and Git as part of the deployment process. Team Collaboration and Support Work closely with global IT teams and stakeholders to meet project objectives. Support NY USD trading teams, particularly during overlapping time zones. Participate in solution design and technical discussions. Help ensure clear communication across international teams.

Join us in revolutionizing how businesses utilize AI technology.In the forthcoming decade, autonomous agents will transform the landscape of our work environments.At Botpress, we empower companies to create and implement sophisticated AI agents that transcend mere conversation and engage in complex business logic.Our product is operational today, scalable across various industries, regions, and countless applications.Recognized as the 3rd fastest-growing B2B AI startup globally, we are leading the charge in the AI revolution, offering the most utilized platform for advanced AI agents.The journey ahead is ambitious, and the opportunity is exceptional. We adopt a strategic approach to growth: product-led, capital-efficient, and intensely focused.If you aspire to develop foundational technology for one of the most significant transitions in software, we invite you to apply.

Join mila-2 as a Full Stack Software Developer focused on combating misinformation. In this critical role, you will leverage your technical skills to develop innovative solutions that enhance the accuracy and reliability of information online. Collaborate with a talented team dedicated to making a meaningful impact in the digital landscape.

About UsAt Industrious, we are the foremost provider of premium workplace-as-a-service solutions, proudly hosting the industry's highest-rated work environments. Our mission revolves around crafting exceptional experiences for teams of all sizes and stages, including our own. We believe that a fulfilling workday is created through collaboration and innovative problem-solving. We seek individuals who are eager to think creatively and excel in a truly cooperative atmosphere. As a part of our team, your ideas will be welcomed, and every success celebrated. We are passionate about making a significant impact on our members' workplace experiences.We foster an inclusive environment where everyone can be their authentic selves. A rich diversity of backgrounds, ideas, and perspectives is essential for us to deliver outstanding workplace experiences for our members and each other. At Industrious, individuality is valued and celebrated, enabling us to achieve remarkable results together as a unified team.To explore our career opportunities, visit www.industriousoffice.com/careers.Role OverviewTechnology is the cornerstone of Industrious' vision to transform the modern workday. As a Full Stack Developer within our Marketing team, your role extends beyond mere coding; you will serve as a pivotal connection between our innovative vision and the digital experience that engages and converts our target audience.Our engineers are driven by curiosity, take on significant challenges, and are redefining the coworking landscape. If you are prepared to elevate your skills beyond basic CRUD applications and develop scalable, integrated solutions for a rapidly expanding business, this opportunity is for you.Your ContributionsIn this position, you will focus on designing our public-facing web applications and developing intelligent marketing automation systems to ensure effective audience engagement. Your key responsibilities will include:Enhancing Our Digital Front Door: Take charge of the development and optimization of our high-traffic marketing web applications, including our blog and essential landing pages, guaranteeing they are responsive, robust, and visually appealing.Boosting Growth Through Automation: Create and implement powerful automation systems that link our core technologies, utilizing tools such as HubSpot and Kafka.

Medfar is looking for a Senior Full Stack Developer to join the team in Montreal. This role centers on building and maintaining software that helps clinics and care providers deliver better patient care. The focus is on SaaS products tailored for the healthcare industry. Role overview This position involves designing, developing, and supporting solutions that streamline healthcare operations. The work directly impacts how clinics manage their workflows and how patients receive care. What you will do Develop and maintain features across the full stack for Medfar’s healthcare SaaS platform Work closely with colleagues to deliver reliable and scalable software Contribute to projects that improve clinic operations and patient outcomes Location This position is based in Montreal.

Mandatory Residency in Greater Montreal.This is a hybrid position requiring in-office presence for the initial three months, transitioning to a flexible arrangement with 3 to 4 days in the office thereafter.As a part of the XTM portfolio, Consoltec specializes in developing the innovative FlowFit application, designed specifically for translation companies and linguistic services.At XTM Group, we are committed to providing state-of-the-art solutions in translation management, empowering enterprises to efficiently access global markets through our industry-leading platform that automates and manages every aspect of the localization process.Our workplace culture is grounded in collaboration and a shared passion for language technology, fostering an inclusive environment where every employee feels valued and can contribute meaningfully. Our core values guide our actions, helping us strive towards our vision of becoming the top Translation Management System for enterprises.We are currently in search of an Intermediate/Senior Full Stack Developer specializing in .NET C# to join our dynamic team at our Montreal office located in the Angus Technopole district.If you are a dynamic, creative individual eager to tackle challenges, we want you on our team! As a lead .NET C# Full Stack Developer, you will play a crucial role in the development and implementation of our FlowFit solution, actively participating in the design and analysis of our clients’ unique needs.Join our team to:Contribute to significant projects for international clientsCollaborate with a talented team in a supportive environmentThrive in an agile work settingKey Responsibilities:Engage in the development of our FlowFit solutionDesign and develop user interfacesImplement proactive monitoring and suggest enhancements

Join Our TeamYou are driven by the challenge of developing innovative solutions in the gaming industry? Do you thrive in a collaborative and dynamic environment? We are looking for a highly skilled Senior Full-Stack Developer to join our dedicated team focused on creating dashboards for game publishers using Unity Ads!In this pivotal role, you will be instrumental in the development and maintenance of Unity Ads dashboards. You will design and implement robust, scalable, and secure software systems while collaborating with cross-functional teams to identify needs and continuously improve the performance and reliability of our products. Our new Vector platform has seen remarkable success, and you will directly contribute to sustaining this momentum.Your ResponsibilitiesDevelop complex dashboard experiences that transform multidimensional data into clear, reliable, and actionable workflows for users.Manage front-end features from inception to production, closely collaborating with Product and Design teams to shape requirements, UX decisions, and execution plans.Work with Product teams to create intuitive interactions in the dashboards and manage their functionalities based on user needs and indicators.Design and develop shared UI components, patterns, and interaction models to be used across various dashboard interfaces.Collaborate with engineers from different dashboard teams to review designs and code, promoting consistency, performance, and maintainability.Lead the implementation of data-driven user interfaces, ensuring that front-end data models are resilient to changes and edge cases.Identify UX, performance, and reliability issues through hands-on investigations, metrics, and user feedback, and implement improvements until resolution.Participate in front-end architecture decisions, balancing rapid execution with long-term usability and extensibility.

ABOUT XSOLLAXsolla is a leading global commerce platform that equips developers with innovative tools and services to navigate the complexities of the video game industry. From indie developers to major AAA studios, Xsolla empowers its partners to fund, distribute, market, and monetize their games effectively. With a strong belief in the future of gaming, we are dedicated to connecting opportunities and continuously providing new resources to creators. Headquartered in Los Angeles, California, we serve as the merchant of record and have successfully assisted over 1,500 game developers in reaching wider audiences and expanding their businesses globally. Our mission is to ensure developers have everything they need to thrive in the gaming landscape.Position Overview: As a Full Stack AI Engineer, you will design and develop cutting-edge applications that power generative AI platforms.Key Responsibilities:- Architect and develop full-stack applications tailored for generative AI solutions.- Create and maintain dynamic frontend applications using Next.js with integrated API routes.- Design and implement visually engaging and responsive user interfaces utilizing Tailwind CSS / Shadcn or similar CSS libraries.- Write clean, efficient, and scalable code using Python and TypeScript.- Collaborate with various libraries or frameworks based on project needs.- Stay informed about the latest trends in AI and associated technologies, frameworks, and tools (e.g., MCP, agentic systems).- Develop APIs and infrastructure supporting LLM-based features and workflows.- Work closely with frontend, ML, and product teams to deliver seamless AI experiences.- Optimize backend systems for enhanced performance, scalability, and reliability.