Moving from a custom-built eCommerce platform to Shopify Plus is one of the most impactful infrastructure decisions you can make.

It means leaving behind the dev burden — and unlocking faster performance, a rich app ecosystem, and a scalable foundation for growth.

But with custom builds, no two migrations are the same.

You’ll need to preserve your customer experience, rebuild the right workflows, and rethink delivery and checkout logic for Shopify’s ecosystem.

This guide walks you through what to expect — and how to migrate successfully.

🧠 Why Brands Leave Custom Platforms

Custom platforms can feel powerful — until they start holding you back:

• Expensive, ongoing dev work for basic changes

• Inconsistent UX across devices

• Checkout logic that breaks or can't scale

• No app ecosystem → everything is built from scratch

• Slow delivery improvements and shipping coordination

• Hard to test and measure performance updates

Shopify Plus gives you:

• A fast, stable commerce engine

• Built-in checkout and order infrastructure

• Flexibility through themes, apps, and low-code extensions

• Tools like Shopify Flow, B2B, and Checkout Extensibility

• A modern delivery logic layer via apps like Flare

🛠️ What You’ll Need to Migrate from a Custom Platform

Product Data
– Export SKUs, variants, pricing, and any custom attributes
– Shopify supports metafields to replicate custom logic

Navigation Structure
– Rebuild your taxonomy using Shopify’s collection and tag system
– You may need to rethink categories vs filters

Theme Design & UX
– You can recreate your existing site, or use the opportunity to refresh the design with a Shopify 2.0 theme

Media & Content
– Migrate product images, homepage banners, icons, and content blocks manually or via theme sections

Customer Accounts
– Export user data, then use Shopify’s customer import tools or send reset invites to help re-onboard

Order History
– Import historical orders for reporting continuity — tools or custom APIs can help

SEO: URLs, Redirects, Meta Data
– Shopify uses a structured URL format — so plan for 301 redirects and meta preservation to protect rankings

Payments & Taxes
– Shopify Payments or preferred gateways + built-in tax configuration for global selling

Delivery & Shipping Logic
– You’ll need to rebuild all delivery rules using Shopify-native tools or apps
– Custom logic (cutoffs, ZIP rules, multi-country logic) is best rebuilt with apps like Flare

Integrations
– Reconnect your ERP, WMS, CRM, support, subscriptions or custom services via APIs or Shopify apps

🔍 What’s Different Between Custom Platforms and Shopify Plus?

There’s no direct mapping from custom platforms — but here are the biggest mindset shifts:

Themes & Frontend
– Custom: usually built from scratch, bespoke structure
– Shopify: structured via themes (Liquid + JSON templates) with visual editors

Shipping & Delivery Rules
– Custom: logic lives in your backend, often hardcoded
– Shopify: rules live in Shipping Profiles or apps (e.g. Flare), designed for flexibility

Checkout
– Custom: usually fully built in-house
– Shopify: native checkout, with Checkout Extensibility available to Plus merchants for adding logic, upsells, or integrations

Dev vs No-Code Balance
– Custom: fully developer-dependent
– Shopify: teams can move faster using apps, Flow automations, and theme sections

App Ecosystem
– Custom: everything is built or maintained manually
– Shopify: thousands of pre-built, high-quality apps for marketing, shipping, and operations

⚠️ Common Migration Pitfalls from Custom Builds

• Overbuilding — trying to replicate everything exactly vs improving weak spots

• SEO loss — failing to match URL structure and redirect properly

• Delivery logic gaps — no clear rebuild plan for shipping logic or delivery scheduling

• Checkout inconsistency — especially if the old flow had heavy customisation

• Lack of operational tooling — forgetting to replace internal dashboards, tagging rules, or fulfilment flows

📦 Rebuilding Delivery Logic on Shopify

Many custom platforms handle:

• Dynamic delivery dates

• ZIP-specific delivery windows

• Product-based shipping rules

• Surcharges or delivery fees

• Complex fulfillment timing

These rules don’t automatically carry over.

On Shopify, you’ll need to rebuild this logic with native tools — or use apps like Flare that handle advanced delivery rules.

Flare gives you:

• A powerful delivery date picker at product, cart, or checkout

• Rules by product, location, shipping method, and day of the week

• Cutoffs, surcharges, lead times, and blackout date management

• Support for mixed baskets and multi-region logic

• Integration with carriers and 3PLs

✅ Shopify Plus Migration Checklist (Custom Platform Edition)

Before Migration:

• Audit your store: product structure, theme logic, delivery flows, UX issues

• List out all custom logic — especially anything tied to checkout or fulfilment

• Identify which workflows need replacing (vs removing)

During Migration:

• Export/import products, media, customer data, and order history

• Choose or build a Shopify 2.0 theme

• Set up collections, navigation, and filtering

• Rebuild delivery logic using Shopify + Flare

• Rebuild key automations (tagging, fulfilment, 3PL routing)

• Set up SEO redirects and verify with Google Search Console

Post Launch:

• Monitor conversion rates, especially on mobile

• Track delivery-related support tickets

• Gather feedback on the new shopping and checkout experience

• Optimise rates, shipping rules, and customer communication based on insights

🚀 Ready to Replatform?

A move from custom to Shopify Plus can reduce maintenance burden, increase conversion, and unlock scalable operations.

The key is to rebuild with purpose — and design for the customer experience you want going forward.

→ Need help rebuilding delivery logic in Shopify Plus?

→ Explore Flare for Shopify Plus