Senior Software Engineer (SDE II - Python) - Remote/Canada

About the Role

Fulfil is hiring a Senior Software Engineer (Python) for a Remote role (Canada) Toronto to become a key technical partner for our North American customers, our India-based engineering team, and our Product Lead for Integrations.

While we have a small team in Toronto today, you will be one of the early senior engineering hires in Canada. Your impact will be outsized, and you’ll help shape how Fulfil builds, supports, and scales engineering in North America.

You will own integrations (3PLs, carriers, sales channels, and merchant-specific operational logic) end-to-end: scoping, designing, building, reviewing, deploying, supporting, and improving production systems used by high-growth commerce brands.

You will work across product engineering, integrations, support, implementation, and customer-facing technical problem-solving. Fulfil does not operate with a traditional product management layer, so our best engineers are expected to think deeply about the customer problem, make sound product judgments, and build solutions that scale.

This is a high-autonomy role for someone who wants to be close to the business, the code, and the customer.

Why Fulfil

Fulfil is a technical founder-led, bootstrapped company in our 11th year of operations. We're a small team of exceptional engineers powering millions of orders for brands like HexClad, Ridge Wallet, and Caraway. No red tape. No product managers. No layers of approval. You'll own critical systems, make architectural decisions, and work directly with merchants- sometimes in their warehouses too. You'll ship to production in your first two weeks.

You'll work directly with our Product Support team, who talk to merchants daily. They bring you real problems, you propose solutions, you ship. No PRDs. No one translating customer pain through three layers of abstraction.

At a large company, senior engineers write docs and attend meetings. Here, you'll design systems that process millions of transactions monthly and ship them yourself.

The Team

The Integrations team connects Fulfil to Shopify, Amazon, marketplaces, 3PLs, carriers, and EDI. We process thousands of orders per minute. Mission: integrations are reliable, scalable, debuggable by customers, and fast to build.

• Location: Remote Canada (some in person travel during onboarding)
• Type: Full-Time
• Expected Start Date: Immediately
• Compensation: $160,000 - $180,000 CAD

What You’ll Do

• Build Production-Grade Integrations: Design, build, and maintain Python integrations across commerce, logistics, finance, and fulfillment workflows, including 3PLs, carriers, sales channels, and merchant-specific operational logic.
• Own the Full Lifecycle: Take work from customer problem to technical design, implementation, code review, deployment, production support, and continuous improvement. At Fulfil, raising the PR is not the finish line.
• Solve Real Customer Problems: Work directly with customers, support, and implementation teams to diagnose issues, understand operational workflows, and identify product gaps. You’ll translate messy real-world problems into durable technical solutions.
• Raise the Engineering Bar: Partner with our India-based engineering team on architecture, code quality, reviews, reliability, and maintainability. “It works” is not enough; the code needs to be understandable, supportable, and scalable.
• Scale North American Engineering Coverage: Help create stronger EST technical coverage for merchant escalations, integration support, and customer-facing discovery as Fulfil builds its Toronto engineering presence.
• Turn Patterns Into Product: Identify recurring integration needs and customer pain points, then turn one-off solutions into scalable product capabilities.
• Use AI Thoughtfully: Use AI tools as a force multiplier for engineering velocity while maintaining strong judgment, review discipline, and code quality.
• Work Close to Leadership: Collaborate with technical leadership, including our founder/CEO, on product and engineering decisions where the best answer is not always obvious.

A Typical Week

• Monday: Lead design review for re-architecting the integration framework. Goal: reduce time-to-build from weeks to days.
• Tuesday: Build the core framework. Test by migrating an existing carrier integration. Validate it handles 2000 shipments/minute.
• Wednesday: Call with a merchant's technical team. They're setting up EDI with a major retailer. Design the solution together.
• Thursday: Code review for two SDE-IIs on new channel integrations. Guide them on idempotency, retry patterns, rate limiting.
• Friday: Ship the new framework. Watch an SDE-II build a new 3PL integration in 3 days instead of 3 weeks.

What You'll Own

• Order processing architecture: allocation, routing, splitting
• Inventory system reliability at scale
• WMS scalability for high-SKU warehouses
• Technical direction (with Product Lead)
• Mentoring engineers

What We're Looking For

• 4-6 years building backend systems
• Systems that process millions of transactions
• Expert Python, large codebases
• Deep PostgreSQL: partitioning, query planning, performance
• Strong debugging across services
• Clear communication with technical and non-technical people

Tech Stack Python, PostgreSQL, Redis, Celery, RabbitMQ, SQLAlchemy, Kubernetes, pytest, Claude Code