Leon Haggarty

Frontend DRI for Instant Unstaking, shipping a new liquidity flow with rollout safety, dogfooding, production validation, and resilient UX for failure modes.

Founding frontend engineer for the Coinbase Lend MVP, delivering core product surfaces and flows with a scalable foundation for eligibility/content configuration and analytics hooks.

Improved reliability and observability across staking by tightening error handling and upgrading monitoring practices to reduce noisy failures and improve on-call clarity.

Built and shipped a cross-platform NHL game simulation product end-to-end: mobile app (React Native/Expo), game API (Next.js), and marketing site (React + Vite), averaging ~15 downloads/week with organic growth.

Engineered a client-side simulation engine with Node.js API fallback and worker threads; integrated live NHL data, real betting odds, and AI-powered summaries for matchup analysis.

Managed player ratings via Contentful CMS with MongoDB Atlas for analytics and accuracy tracking; published to both app stores via EAS Build with feature flags and deep linking.

Built and evolved an internal no-code communications platform, leading a multi-quarter redesign, improving authoring UX and validation, and removing legacy code.

Engineered and optimized the logged-out website by developing reusable templates and URL mapping for product and marketing pages.

Shipped features across the logged-in React web app and React Native mobile apps, including user preferences, growth surfaces, and cross-platform parity improvements.

Shipped customer-facing features for high-traffic e-commerce web apps across Loblaw-owned retail brands, focusing on performance and stability.

Led marketplace integration work to support 3rd-party vendor products and fulfillment flows, partnering with product and backend teams to ship behind feature flags.

Drove a migration to Contentful CMS and introduced reusable UI patterns to accelerate content updates.

Built and shipped features across consumer web, corporate gifting web, internal/admin portals, and a React Native kiosk app.

Coordinated delivery by translating requirements into scoped work and partnering with backend and mobile engineers on APIs and rollout readiness.

Standardized API request/response patterns and improved release quality via QA, debugging, and pre-production validation.

Delivered end-to-end client websites and web apps, from implementation through launch and ongoing maintenance.

Built responsive, SEO-friendly experiences, ensured cross-browser/device compatibility, and incorporated accessibility requirements (AODA).

Owned DNS management, server configuration, SSL setup, and troubleshooting across environments.

Built product features for an emergency responders networking and learning platform, spanning frontend UI and backend business logic.

Partnered with the CTO/lead developer on roadmap planning and iterative releases, turning low-fidelity mockups into production page layouts.

Worked across a full-stack web environment (PHP Laravel/MySQL, JavaScript/React) with basic monitoring and deployment workflows.

Share memorable moments within a video using Hot Potato. Users select, edit, and share content in a no-frills interface.

Built the MVP solo and later partnered with additional developers, managing sprints and project coordination.

Delivered web and mobile app experiences with social sharing built in.