Senior MERN Stack Developer

Sr. MERN Developer – React, Node.js, Express.js, GraphQL & MongoDB Location: Toronto / Waterloo Hybrid (Tue-Thur 8:00 AM EST – 5 PM EST) We are seeking a Senior Full Stack Software Engineer to help drive the roadmap for our Group Benefits Experience assets, our primary digital gateway for Clients and Members managing their benefits and health, and a core part of how Canadians experience benefits online. In this role, you’ll lead the evolution of modern, scalable web applications built with JavaScript/TypeScript, React, Redux, Node.js, Express.js, GraphQL, RESTful APIs, MongoDB and more, while also guiding the modernization of existing .NET and Java systems. You’ll work closely with Software, Quality and Platform Engineers in a collaborative, quality-focused team that takes pride in building reliable, performant, secure, and responsive software. This is an opportunity for an experienced engineer who is passionate about technical excellence, architecture, and building strong, healthy engineering teams in a fast-paced, outcome-driven environment. You’ll bring clarity amid shifting priorities, take ownership of complex engineering work, enable sustainable delivery without compromising quality, and help foster a culture that embraces modern engineering practices, including the thoughtful use of AI. Job Responsibilities Technical Leadership & Architecture • Shape and evolve the end-to-end architecture in partnership with Architecture, Product and Platform teams, influencing technical strategy to modernize our stack and deliver incremental, high-value outcomes. • Design, build, and operate scalable, secure, and high-performing solutions across React front ends, Node.js and Express.js APIs, GraphQL, RESTful services, MongoDB, and .NET/Java ecosystems, ensuring long-term maintainability and performance. • Develop and maintain modern front-end components using React.js, with a focus on clean design, responsiveness, accessibility, performance, and reusable UI patterns. • Build, manage, and evolve back-end services and APIs using Node.js, including RESTful and asynchronous patterns that support scalable digital experiences. • Debug and resolve technical issues across the full stack, identifying root causes and implementing durable, maintainable solutions. Engineering Excellence & Delivery • Elevate engineering maturity by driving best practices in testing, deployment, CI/CD, automation, and operational excellence, using telemetry and observability tools such as New Relic and Moogsoft to continuously improve reliability and system performance. • Deliver high-quality software through disciplined craftsmanship, balancing speed with innovation while consistently raising the bar on code quality. • Write clean, modular, efficient, and scalable code with strong attention to maintainability, security, performance, and long-term platform health. • Take ownership of engineering tasks and outcomes, working independently where needed while staying aligned with team goals, standards, and delivery commitments. • Contribute to secure and reliable deployment practices, including awareness of CI/CD pipelines, cloud deployment patterns, and production readiness standards. Collaboration & Culture • Collaborate deeply across engineering, quality, product, architecture, security, and other cross-functional teams to define, refine, and implement new features that deliver meaningful customer and business value. • Partner with engineers through pairing, mentoring, and thoughtful code reviews to build a strong, inclusive, and high-performing engineering culture. • Contribute to and leverage open source and inner source ecosystems, creating reusable capabilities and sharing knowledge that scales across teams. • Work effectively in Agile and Scaled Agile environments, contributing to planning, delivery, continuous improvement, and team-level execution. AI-Enabled Innovation & Ownership • Champion the responsible use of AI tools to accelerate development, reduce manual effort, and enhance decision-making while maintaining high standards for safety, quality, and compliance. • Bring curiosity, ownership, and pride to your work, continuously learning, improving, and delivering impactful solutions that benefit customers, colleagues, and the broader engineering organization.