Marian Drobchak

Architected and delivered over 20 ecommerce websites across lifestyle, retail, and SaaS sectors using Shopify and React, increasing average conversion rates by 35%. Led redesign of a B2C luxury goods platform, achieving 48% faster load times and a 25% sales uplift through UX and page speed optimization. Integrated Shopify with 3PL logistics providers to automate fulfillment workflows and reduce manual tasks by 60%. Implemented multi-currency and localized checkout systems using Shopify Markets for European customers, improving international sales by 40%. Configured secure payment gateways (Stripe, PayPal, Klarna) compliant with PSD2/SCA standards. Developed custom Liquid and Hydrogen templates aligned with brand guidelines for visually rich product storytelling. Optimized SEO and analytics tracking through GA4, Meta Pixel, and Google Tag Manager for measurable marketing impact. Built reusable React components and hooks, improving development efficiency by 30% across projects. Mentored

Engineered secure authentication flows with Supabase, JWT-based role mapping and route protection across multiple enterprise-grade applications. Developed and optimized Next.js/React dashboards with SSR for improved SEO and load performance, reducing TTFB by 35%. Delivered Stripe Checkout and PayPal Smart Button integrations, handling server-side order creation, webhooks, and persistent order states in Supabase. Spearheaded integration of OpenAI conversational APIs, enabling contextualized prompts with real-time session handling. Rebuilt a failing shopping cart system by introducing persistent state management with Supabase and React Context API, achieving 99.9% transaction accuracy. Enhanced Row-Level Security policies in Supabase to secure user data and enforce RBAC without performance trade-offs. Migrated critical services to Vercel, configured environment variables and secrets for secure deployments across dev/staging/production. Created scalable backend endpoints with Next.js API

Engineered secure authentication flows with Supabase (JWT-based role mapping and route protection), built Next.js/React dashboards with SSR to improve SEO and load times. Implemented Stripe Checkout and PayPal Smart Button integrations with server-side order creation and webhooks, persisting orders in Supabase. Led integration of OpenAI conversational APIs for contextual prompts and real-time session handling. Rebuilt a fault-tolerant shopping cart with persistent state via Supabase/React Context API, achieving 99.9% transaction accuracy. Tightened data security by expanding RLS policies in Supabase and enforcing RBAC. Moved services to Vercel with secure environment and secret management. Created scalable Next.js API routes for multi-step checkout and AI-driven recommendations. Automated email notifications and invoicing workflows for compliance. Wrote unit/integration/end-to-end tests using Jest and Cypress with 90%+ coverage. Collaborated with designers to implement responsive UI/UX