Full Stack Software Engineer - Canada

About ReacherReacher is a YC backed AI SaaS platform building the operating system for TikTok Shop brands and creators. We’re backed by Y Combinator, Pioneer Fund, Rebel Fund, and operators including Steve Huffman (CEO of Reddit), Matteo Franceschetti (CEO of Eight Sleep), Theo Browne (t3.gg), Kulveer Taggar (Zeus Living), and Jake Mintz (Bump). We have years of runway and are scaling fast with some of the biggest brands in the world (UnderArmour, Hanes, Logitech, Goli)Our vision is to become the Hubspot for creator marketing, powering brands and creators to connect and grow across all commerce platforms (Youtube Shopping, Instagram Shopping, Shopify, Amazon). We're building key infrastructure for the creator economy and implementing AI with the world's largest brands and creators.Your work will directly impact users on day 1 - our user base depends on our product daily.We build with AI, not around it. Our engineering team uses Claude Code and agentic coding tools as our primary development environment. If you're spending your days directing AI agents to ship code while you focus on architecture, review, and system design — and you can't imagine working any other way — keep reading.What You'll DoOwn and lead product features end-to-end: research, design, implement, test, and shipLead and shape engineering architecture - set standards for code quality, testing, and development practices across the stackMentor and guide other engineers in adopting AI-native workflows, establishing best practices and patternsTalk directly to customers and translate vague requirements into polished user experiencesDesign scalable backend systems (Python, FastAPI, PostgreSQL, GCP)Build responsive, delightful UIs (React, TypeScript, Tailwind, shadcn/ui)Write clean, maintainable, and testable code with minimal oversightDrive architectural decisions and engineering processes that maximize AI-assisted development velocityShip fast and learn fast - high urgency environmentYou're a Fit IfEngineering Foundations: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 frontendCare deeply about product, design, and user experience—not just codeHave 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 environmentResourceful and thrive in ambiguous environments—you figure things out independentlyHave strong product intuition and can push back on requirements when needed to improve outcomesAI-Native Development: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 experimentStrong 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 correctionCan demonstrate recent AI-native work - you've shipped meaningful projects in the last 90 days where AI coding tools were your primary development environmentTechnical Skills We ValueAI and Agentic Development:Claude Code proficiency: understanding of modes, context engineering (CLAUDE.md), custom commands, MCP integrations, and subagent coordinationAI-driven development workflows and effective prompt engineeringAbility to decompose complex engineering work into tasks suitable for AI assistanceStrong judgment for when to leverage AI vs. when to code directlyExperience verifying and reviewing AI-generated code for correctness, security, and maintainabilityBackend:Python, FastAPI, PostgreSQLSystem design and scalable architectureGCP/cloud infrastructureAPI design (REST/GraphQL)Frontend:React, TypeScript, Next.jsTailwind CSS, shadcn/uiState management (Redux, Zustand, React Query)Frontend performance optimization and accessibility (WCAG)General:Testing frameworks (Jest, React Testing Library, Cypress/Playwright)Code reviews, documentation, and establishing conventionsProduct analytics tools (Amplitude, Mixpanel) for data-driven developmentBonus Points IfExperience building autonomous agents with the Claude Agent SDK or similar agentic frameworks—you understand multi-agent orchestration, MCP integrations, and production agent deploymentExperience with AI image/video generation or manipulation - familiarity with tools like Midjourney, Runway, Stable Diffusion, Sora, or integrating generation APIs into product workflowsYou've worked at an early-stage startup or been a first/early engineering hireYou've built internal tooling, dashboards, or systems that scaled to thousands of usersYou've led technical initiatives or mentored junior engineersYou've built or maintained design systemsYou're curious about AI, e-commerce, or automation—we work in that spaceYou've shipped side projects or contributed to open-sourceYou've worked directly with designers and can contribute to design discussionsWhy Join UsPost-revenue company solving real problems for real customersBe a technical leader—define our engineering culture and standards as we scaleHigh autonomy and visibility—no boring ticketsYour code reaches users within days, not monthsStrong engineering-first culture that embraces cutting-edge AI toolsShape both the product and the companyWhen ApplyingPlease send a short note about a complex problem you solved or a new skill you mastered specifically using an AI-driven workflow. GitHub/LinkedIn/resume is great, but we care more about how you think, build, and leverage AI. If you have examples of projects where AI coding tools were central to your workflow in the last 90 days, we'd love to see them.