Full Stack Software Engineer Canada

Reacher is a YC backed AI SaaS platform building the operating system for TikTok Shop brands and creators. The Full Stack Software Engineer will own and lead product features, mentor engineers, and design scalable systems, all while leveraging AI tools to enhance development processes.

Responsibilities:

• Own and lead product features end-to-end: research, design, implement, test, and ship
• Lead and shape engineering architecture - set standards for code quality, testing, and development practices across the stack
• Mentor and guide other engineers in adopting AI-native workflows, establishing best practices and patterns
• Talk directly to customers and translate vague requirements into polished user experiences
• Design scalable backend systems (Python, FastAPI, PostgreSQL, GCP)
• Build responsive, delightful UIs (React, TypeScript, Tailwind, shadcn/ui)
• Write clean, maintainable, and testable code with minimal oversight
• Drive architectural decisions and engineering processes that maximize AI-assisted development velocity
• Ship fast and learn fast - high urgency environment

Requirements:

• 2–6 years of professional full-stack experience at a product-first company or FAANG-level environment (Senior SDE ownership expected)
• Comfortable building features across the entire stack—from schema design and backend APIs to pixel-perfect, accessible frontend
• Care deeply about product, design, and user experience—not just code
• Have owned something meaningful end-to-end (a product module, infrastructure refactor, major feature launch)
• Can set standards for engineering quality and architectural decisions in an AI-native environment
• Resourceful and thrive in ambiguous environments—you figure things out independently
• Have strong product intuition and can push back on requirements when needed to improve outcomes
• AI coding experience is your most important and necessary skill - you have deep understanding of modern coding tools, specifically Claude Code, and are proficient with its various modes (Interactive, Plan, Headless, Agent Teams, Delegate)
• You're 'AI-pilled' when it comes to problem-solving - you tackle any new problem, skill, or architectural challenge by leveraging AI tools and an AI-driven workflow. This is your default approach, not an experiment
• Strong systems thinking and architectural awareness - you direct AI to build while you architect, review, and verify. You know when AI output is correct and when it needs correction
• Can demonstrate recent AI-native work - you've shipped meaningful projects in the last 90 days where AI coding tools were your primary development environment
• Claude Code proficiency: understanding of modes, context engineering (CLAUDE.md), custom commands, MCP integrations, and subagent coordination
• AI-driven development workflows and effective prompt engineering
• Ability to decompose complex engineering work into tasks suitable for AI assistance
• Strong judgment for when to leverage AI vs. when to code directly
• Experience verifying and reviewing AI-generated code for correctness, security, and maintainability
• Python, FastAPI, PostgreSQL
• System design and scalable architecture
• GCP/cloud infrastructure
• API design (REST/GraphQL)
• React, TypeScript, Next.js
• Tailwind CSS, shadcn/ui
• State management (Redux, Zustand, React Query)
• Frontend performance optimization and accessibility (WCAG)
• Testing frameworks (Jest, React Testing Library, Cypress/Playwright)
• Code reviews, documentation, and establishing conventions
• Product analytics tools (Amplitude, Mixpanel) for data-driven development
• Experience building autonomous agents with the Claude Agent SDK or similar agentic frameworks—you understand multi-agent orchestration, MCP integrations, and production agent deployment
• Experience with AI image/video generation or manipulation - familiarity with tools like Midjourney, Runway, Stable Diffusion, Sora, or integrating generation APIs into product workflows
• You've worked at an early-stage startup or been a first/early engineering hire
• You've built internal tooling, dashboards, or systems that scaled to thousands of users
• You've led technical initiatives or mentored junior engineers
• You've built or maintained design systems
• You're curious about AI, e-commerce, or automation—we work in that space
• You've shipped side projects or contributed to open-source
• You've worked directly with designers and can contribute to design discussions