Automated Web Proposal & Dynamic Checkout Ecosystem for Shopify

EU Art Framing Brand - End-to-End Web Proposal System

Overview
Built a complete automated proposal platform for a Dutch e-commerce brand specializing in custom art framing. The client was sending proposals manually as PDF attachments with no tracking, no direct checkout, and no automation. I replaced the entire workflow with an interactive web-based proposal system, internal admin tooling, Shopify checkout integration, and behavior-driven email flows, all connected through a single Google Sheet as the operational hub.

What I Built
Dynamic Proposal Webpage
A responsive, brand-matched proposal page that hydrates in real time from a Google Sheet. Each customer gets a unique URL tied to their order reference. The page displays three framing options (Edits) with image carousels, pricing, and direct checkout buttons, replacing the static PDF entirely.

Google Sheets Sidebar Admin Tool
Built a custom Apps Script sidebar inside Google Sheets that lets the client create and manage proposals without touching any external tool. Staff can upload artwork images, fill in proposal details, and trigger automations, all from within the Sheet they already work in.

Shopify Integration via Draft Orders API
Connected the proposal checkout buttons to Shopify via the Draft Orders REST API, generating unique checkout URLs with line item properties (frame specs, photo reference, order reference) passed through to the order in Shopify Admin. Internal fields are hidden from customers using Shopify's underscore prefix convention.

Credit-Optimized Make.com Automation Pipeline
Designed an event-driven automation architecture using webhooks instead of interval-based polling, cutting Make.com credit consumption by up to 90%. Key flows include: inquiry form to Google Sheet, proposal send trigger, status update on send confirmation, and revision request notifications.

Klaviyo Email Lifecycle Flows
Configured behavior-driven email flows using custom Klaviyo metrics and profile properties. Flows include: proposal delivery email, follow-up reminder if the proposal has been viewed but not acted on, and a separate reminder if the email has not been opened after a set period.

Multi-Layer Pricing Engine
Built a three-tier pricing fallback system in vanilla JS: proposal-level overrides take priority, followed by global defaults set in Row 2 of the Sheet, with hardcoded safety values as a last resort. Ensures pricing on the proposal page always matches the Shopify checkout total.

Results

• Replaced a fully manual PDF-based sales process with a zero-touch automated workflow

• Achieved full price consistency between the interactive proposal calculator and Shopify checkout

• Reduced Make.com credit usage by up to 90% through webhook-first architecture

• Internal team can create and send a complete, branded proposal in minutes with no technical knowledge required