Full-Stack Engineer / Technical Lead

Company Description Rezz is a Shopify app that offers a simpler, more seamless way for e-commerce merchants to offer gifting to their customers. It helps merchants reduce friction in the gifting experience, drive incremental sales, reach new customers, and cut waste from unwanted gifts. Rezz integrates directly with merchants’ existing e-commerce infrastructure. Currently available for Shopify merchants, Rezz focuses on delivering smarter, more efficient digital gifting experiences.Role Description The Full-Stack Engineer / Technical Lead will be responsible for designing, building, and maintaining scalable web applications that power Rezz’s gifting technology. The role involves leading technical decision-making, implementing front-end interfaces, developing back-end services and APIs, and ensuring secure, high-performance integrations with e-commerce platforms (Shopify today, new platforms in the future).Day-to-day responsibilities include writing clean, testable code, reviewing contributions from other engineers, troubleshooting production issues, and collaborating closely with product, design, and business teams to deliver new features. The Technical Lead will also help define architecture, improve development processes, and mentor teammates to support a high-quality engineering culture.QualificationsStrong TypeScript and Node.js experienceAdvanced experience with React and Next.js, React Router v7/Remix and PreactPolaris 13.9.5, App Bridge React 4.2.10Strong PostgreSQL and Prisma knowledgeGraphQL APIs built on Apollo Server and NexusClerk as an identity provider (sessions for the consumer app, admin, and mobile). ⁠⁠Experience receiving and processing webhooks (Shopify and Clerk)⁠Experience with background jobs and event-driven workflows, including retries when processing failsMobile applications built with Capacitor, React Native, and FlutterExperience deploying and operating production applications on Vercel or similar cloud platformsComfortable working with AWS services, particularly S3Datadog and Sentry for monitoring and incident-managementStrong GitHub workflows, code-review and release-management practicesShopify experience — strong plusProven experience building public Shopify appsShopify Admin GraphQL APIShopify webhooks and OAuthTheme App ExtensionsApp Embeds and cart-drawer integrationsCheckout and Thank You Page extensionsShopify orders, draft orders, fulfillment and gift-card workflowsShopify Billing API and app subscriptionsShopify Markets, currencies, taxes and shipping logicUnderstanding of Shopify app-review requirementsAbility to test across different Shopify themes without breaking merchant storefrontsResponsibilitiesTaking technical ownership of Rezz’s Shopify app, merchant hub, recipient experience and Rezz WalletUnderstanding and documenting the existing architecture and codebaseResolving production issues quickly and preventing repeat incidentsImproving platform performance, stability and securityManaging deployments, monitoring, backups and disaster recoveryBuilding new features from product requirements through production releaseManaging integrations with Clerk, Neon, Postmark, Mux, Cloudflare and other servicesStrengthening automated testing, QA and theme-compatibility testingMaintaining clear staging, release and rollback processesPrioritizing technical debt alongside product developmentSupporting future integrations with platforms