Senior Fullstack Developer

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Fullstack Developer based in Canada. This role is a front-end-leaning full-stack engineering position focused on building high-performance, scalable digital applications. You’ll work end-to-end across modern user interfaces, APIs, services, and data layers, with a strong emphasis on React, Next.js, and TypeScript. Reporting to the Technical Director, you’ll contribute to architecture and technical direction while remaining hands-on in development. You’ll collaborate directly with clients, product managers, designers, and engineers to turn complex requirements into polished solutions. The role also provides opportunities to mentor other developers and influence modern engineering practices. It’s well suited to a technically strong engineer who enjoys solving challenging problems in a fast-paced, client-facing digital agency environment. Accountabilities: Lead the architecture, design, and development of complex full-stack applications using React, Next.js, TypeScript, and supporting Node.js APIs and services. Design and develop RESTful and/or GraphQL APIs, including data models, authentication, integrations, and connections to SQL or NoSQL databases. Translate business requirements, client needs, and UI/UX designs into scalable, responsive, accessible, and high-performing full-stack solutions. Collaborate closely with clients, product managers, UI/UX designers, and engineering teams throughout the development lifecycle. Serve as a technical expert across the front-end and back-end stack, providing guidance and best-practice recommendations to junior and mid-level engineers. Drive adoption of modern development techniques, tools, frameworks, and engineering practices across the technology stack. Ensure applications meet high standards for performance, scalability, security, maintainability, and reliability from the UI through the API and data layers. Leverage Next.js server-side capabilities, including SSR, React Server Components, and API routes, where they improve application performance or developer experience. Participate in code reviews across the stack, promoting quality, consistency, maintainability, and adherence to established standards. Troubleshoot and resolve complex technical issues spanning front-end, API, and data layers. Communicate technical concepts, solutions, and project progress clearly to both technical and non-technical stakeholders, including clients. Stay current with emerging front-end and back-end technologies and evaluate new approaches that could improve project outcomes. Contribute to project planning, technical estimation, documentation, and broader technical decision-making. Requirements Bachelor’s degree in Computer Science, Software Engineering, or a related field, or equivalent practical experience. 5+ years of professional experience as a Front-End or Full-Stack Engineer, with strong expertise in React, Next.js, and TypeScript. 2+ years of hands-on backend development experience using Node.js frameworks such as Express or Nest.js and working with relational or NoSQL databases such as PostgreSQL or MongoDB. At least 3 years of experience working within a digital agency environment, including direct client interaction and relationship management. Proven ability to build responsive, accessible, performant web applications supported by well-designed APIs and data models. Deep understanding of modern JavaScript across both client-side and server-side development. Extensive experience with state management technologies such as Redux, Zustand, or Context API. Practical experience with SSR, React Server Components, and static site generation as approaches for connecting front-end and back-end functionality. Strong knowledge of front-end build tools and package managers, including Webpack, Vite, npm, or Yarn. Experience with testing frameworks and tools across the stack, such as Jest, Vitest, React Testing Library, Cypress, or Supertest. Familiarity with Git-based development workflows. Excellent communication, interpersonal, and presentation skills, with the ability to explain complex technical concepts to diverse audiences. Strong ability to manage multiple priorities, meet deadlines, and perform effectively in a fast-paced, client-facing environment. A portfolio demonstrating complex full-stack projects is a significant plus. GraphQL API design and schema architecture experience is a plus. Experience with cloud platforms such as AWS, Azure, or Google Cloud is a plus. Familiarity with Docker, containerization, or serverless deployment patterns is a plus. Understanding of SEO best practices for front-end development is a plus. Contributions to open-source projects are a plus. Benefits Full-time, remote position based in Canada. Remote-first work environment. Opportunities to work on innovative digital products and technology projects with direct client exposure. High degree of autonomy and involvement in technical and creative decision-making. Supportive environment focused on professional development, learning, and expanding technical expertise. Opportunities for internal and external exposure and continued career growth. Culture emphasizing teamwork, curiosity, courage, and passion. Equal opportunity workplace with accommodation available to candidates upon request.