Senior Backend Software Engineer

A fast-growing, AI start-up is seeking a Senior Backend Software Engineer to join its highly collaborative, cross-functional team. This is a unique opportunity to build impactful systems from the ground up in an engineering-first environment where technology drives every decision. You’ll play a key role in shaping scalable infrastructure and delivering best-in-class experiences for end users. This role is perfect for someone who enjoys autonomy, thrives on solving complex technical challenges, and wants to see their work make a real difference — quickly. *******Please note that Sponsorship is not possible for this opportunity, you must have a valid work permit/residence permit to work in Canada******* What You’ll Be Doing Architect, develop, and maintain scalable services, data models, and APIs that power core platform functionality Take full ownership of feature lifecycles — from technical design to deployment and ongoing maintenance Work closely with product, data, and design teams to deliver seamless, user-friendly experiences Build internal tools and infrastructure that improve team productivity and platform reliability Promote and implement engineering best practices, focusing on scalability, performance, and maintainability Contribute to the long-term technical roadmap and system architecture decisions We are seeking a highly skilled Senior Backend Software Engineer to join a fast-paced AI start-up with an excellent team. In this role, you will design, build, and maintain the server-side systems and APIs that power our applications. You will work closely with product managers, frontend engineers, and DevOps to deliver scalable, secure, and high-performance solutions for enterprise customers Key Responsibilities Design, develop, and maintain backend services, APIs, and databases Write clean, efficient, and well-documented code Optimize application performance, scalability, and reliability Collaborate with frontend and product teams to integrate features and deliver end-to-end functionality Implement best practices in security, data privacy, and compliance Participate in code reviews, architecture discussions, and technical planning Monitor, debug, and troubleshoot production systems Contribute to continuous improvement of development processes and tools Requirements 8+ years of experience as a Senior Backend Engineer or in a similar role Strong proficiency in at least one backend programming language (e.g., Java, Python, Go, Node.js, C #) Experience with frameworks such as Spring Boot, Express, Django, or FastAP I Solid understanding of RESTful APIs, GraphQL, or gRP C Hands-on experience with database s (SQL and NoSQL) Familiarity with containerization and orchestratio n (Docker, Kubernetes) Knowledge of cloud platforms (AWS, GCP, or Azure) Experience working with infrastructure Strong understanding of system design, distributed systems, and microservices architectur e Experience working with infrastructure engineers Working knowledge of CI/CD pipelines, Git, and automated testin g Excellent problem-solving skills and attention to detail Strong communication skills and ability to work collaboratively in a cross-functional team Nice to Have Experience with event-driven architecture s (Kafka, RabbitMQ, etc.) Knowledge of DevOps practices and infrastructure as cod e (Terraform, Ansible, etc.) Familiarity with observability tool s (Prometheus, Grafana, ELK stack) Prior experience in a fast-paced startup or agile environmen t What We Offer Competitive salary and benefits package Opportunity to work on impactful, large-scale projects with enterprise customers and on very tangible applications of AI Flexible working arrangements (remote/hybrid options). 1 day a week in the co-working space if you are within the Greater Toronto Area Professional growth and learning opportunities Inclusive and collaborative team culture