Senior Software Engineer, Backend (Consumer Authentication Platform)

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Software Engineer, Backend (Consumer Authentication Platform) based in Canada. This is a senior backend engineering role focused on building secure, reliable, and seamless authentication experiences at significant scale. You will help power critical consumer journeys including sign-up, sign-in, account recovery, checkout authentication, session management, and step-up challenges. The role offers broad technical ownership, from defining architecture and technical requirements through implementation, rollout, and ongoing operations. You will work closely with Product, Security, Fraud, Compliance, Analytics, Data Science, Design, and engineering teams across the organization. A major focus is balancing security, regulatory requirements, fraud prevention, customer experience, scalability, and delivery speed. You will influence the evolution of a reusable authentication platform supporting multiple products, merchants, and geographies. As a senior technical contributor, you will also mentor engineers, raise engineering standards, and lead complex technical and production challenges.