Toronto, ON, Canada About Fulfil Fulfil is the modern ERP for commerce. Built to power the fastest-growing eCommerce brands, our platform brings together order management, inventory, accounting, and more, turning complex operations into a strategic advantage. We’re trusted by brands like HexClad, Ridge Wallet, Caraway, and Resident, and backed by people who want to change the way merchant operations are run. We believe in deep work, radical accountability, and building tools that let sharp people move faster. About the Role As a Python Engineer (Full Stack & AI) at Fulfil, you will design and build next-generation systems that power millions of customer orders and financial transactions for some of the world’s fastest-growing merchants. Our Python-based platform operates at a significant scale, handling millions of transactions per hour. Your work will have a direct impact on system reliability, scalability, and product innovation. You’ll collaborate closely with teammates across Canada, the U.S., and India, working in a highly ownership-driven environment that values clean architecture, pragmatic engineering, and thoughtful problem-solving. Location: Toronto, Ontario (in-office 5 days per week) Type: Full-Time Expected Start Date: Immediately What You’ll Do Own the Full Stack Design, build, and maintain end-to-end functionality across our Python-based platform, from backend services to frontend integrations. Work within a large, mature codebase while contributing to its long-term evolution and scalability. Deliver Features at Speed Lead the design, development, testing, and deployment of new features that directly support high-growth merchants. Balance rapid delivery with long-term maintainability. Apply AI in Production Integrate AI-powered capabilities into Fulfil’s ERP using LLMs (e.g., OpenAI, Anthropic). Build intelligent workflows that enhance automation, decision-making, and merchant experience across orders, financials, and operations. Scale with Confidence Design and optimize REST and GraphQL APIs (600+ endpoints), microservices, and background processing pipelines. Work with containerized infrastructure (Docker/Kubernetes) to support high availability and zero-downtime deployments. Champion Code Quality Refactor and modernize legacy systems. Write well-tested, readable code using pytest. Participate in code reviews and architectural discussions to raise the bar across the team. Build Ecosystem Integrations Develop and maintain integrations with major commerce platforms (Shopify, Amazon) and logistics providers (FedEx, DHL). Ensure reliable data flows across external systems and Fulfil’s core platform. Required Experience 5+ years of experience, ideally, building applications at scale from scratch. Strong experience building large-scale backend systems and microservices using Python. Hands-on experience with ORMs (e.g., SQLAlchemy, Django ORM) and relational databases (PostgreSQL preferred). Proficiency with distributed systems components such as Celery, Redis, RabbitMQ, and background processing. Experience writing automated tests (pytest) and using Git in a collaborative environment. Demonstrated ownership—seeing projects through from design to production and ongoing support. Bonus Points Experience scaling systems at a high-growth tech company. Familiarity with cloud platforms (Google Cloud, Heroku, etc.). Passion for optimizing distributed systems or e-commerce workflows. Domain-Focused Product Engineering: Experience building or scaling production software in commerce, logistics, or operations domains (e.g., order management, inventory, fulfillment, WMS) or in FinTech/financial systems (payments, reconciliation, revenue recognition, invoicing).