When the first order split itself in two

One storefront. The whole portfolio's future.

Gant is an American heritage brand, founded in 1949 on East Coast sportswear and preppy style, today sold in more than 70 countries and 600+ stores worldwide and managed from Sweden. For the Eren Group this project was never just about GANT's Polish store. It was the pilot. If Shopify could carry a brand with this much operational complexity – distributed stock, an ERP backbone, enterprise-grade logistics – then it could carry the rest of the portfolio, Lacoste included. The brief, stripped of its politeness, was: prove the platform, or we rethink the whole roadmap.

That changes how you approach the work. You're not shipping a website. You're building the argument for everything that comes after it.

The part that didn't go to plan first time

The starting point was far from ideal. GANT's main challenge was its previous custom e-commerce engine, which generated technical errors, delivered a weak user experience for both customers (checkout, search, filtering) and the internal team running the store day to day, and severely limited the freedom of sales management. The brand desperately needed a stable platform that would integrate reliably with Comarch ERP, which remained the real operational hub for distributed logistics.

That's why the starting position was awkward in two specific ways, and it's worth being honest about both.

First, there was no direct access to the source database. You're migrating a live premium catalog while reaching for data you can't simply reach in and take.

Second – and this is the one that mattered most – the product catalog and inventory across all four locations – three stores and the central warehouse – had to synchronize with Comarch ERP, which also owns the routing logic deciding which location fulfils each order. That meant integrating far more than stock levels: order status as a single order is split across locations, and shipment tracking as parcels move, and the early integration tests did not pass cleanly. The sync had gaps. On a project whose entire purpose was to prove reliability, the most important connection in the system didn't work properly the first time we tried it.

So we did the unglamorous thing. We treated the Shopify side as our responsibility to get right regardless of where the integration sat: preparing the data layer, structuring and migrating the catalog with Matrixify, configuring inventory and the order-management logic, and working the problem alongside the external ERP integrator rather than throwing it over a wall. The gaps got closed. By the end, the full catalog was migrated, cleaned, and synchronizing with the ERP in near-real time.

The decision that could have gone the other way

The instinct on a flagship premium brand is to build everything bespoke. We argued the opposite. Rather than start from a blank canvas, we adapted GANT's existing global template from the Canadian market and spent our effort where customers would actually feel it – deep personalization to hold the brand standard, custom listing components, dynamic size charts mapped to individual collections, and filtering and search tuned to get a premium buyer to the product faster. It was a speed decision, and on a pilot with a portfolio waiting behind it, speed was a feature.

The harder engineering went where customers don't see it. We built deep, two-way integration between Shopify and Comarch ERP across all four locations – three stores and a central warehouse – so the ERP's own routing logic, including messy real-world cases like one order shipping from two places at once, is reflected back into Shopify in near-real time: inventory, per-shipment order status, and tracking. We automated returns on Shopify Flow and the InPost Quick Returns API, so a standard return now processes itself end to end – picks its own parcel size, keeps the customer informed – and never lands on the customer-service team's desk.

This automation significantly relieved the customer service department by eliminating the need for manual handling of standard logistics operations. At the same time, it increased customer comfort by simplifying the return process in strict accordance with the "one click return" directive.

And we wired the data and consent layer (GA4 and the Conversions API, OneTrust, the Shopify Privacy API, Google Consent Mode v2, plus Emarsys through its Shopify app) so the brand had full control of its data and its consents from the first hour live, not as a later clean-up job.

What's true now

Inventory across all four locations is synchronized in near-real time with the ERP, which decides where orders route and how they split. Standard returns are off the team's plate entirely. Order statuses and shipment tracking flow back from the ERP automatically – the connection that didn't work in early testing now runs quietly in the background.

And the pilot did its job. The launch was held over a live trading weekend, the hard cases worked from the first transaction, and the Eren Group has its template for moving the rest of the portfolio onto Shopify.

And the numbers backed it up

The operational story is the one we see from the inside. The numbers are the part the brand feels – and they held across the new store's first full season, not just a launch-week bump.

We compared March–May 2026 on the new store against the same three months a year earlier on the old platform. Same season, old site versus new, which strips seasonality out and isolates what the migration actually changed.

What's crucial: revenue grew 40% year over year while traffic grew only around 20%. The store didn't just pull more visits – it earned far more from each one. Revenue per session rose 51%, so every visit became worth roughly half again as much as a year before. That gap between revenue and traffic is the whole point of a migration done right.

The biggest shift was on mobile. On the old store the phone experience was the weak link; on the new one, mobile conversion roughly doubled (+98%) and mobile revenue jumped 129% – enough that mobile overtook desktop as the brand's larger revenue channel for the first time. That's the signature of moving to a modern, mobile-first storefront.

It changed the economics of marketing, too. The same paid budget now lands on a store that closes far better: conversion from paid search more than tripled (+210%), and revenue from Performance Max campaigns grew several times over. The migration didn't just improve the store – it multiplied the return on every marketing złoty spent against it.

And it won on quality, not just volume. The new store drew in more – and colder – top-of-funnel traffic, yet overall conversion still climbed 47% and purchases 34%. A store that converts better even as its traffic gets harder is a store that is genuinely better. Much of that traces back to the build decisions: product views more than doubled year over year as the new listing components, size charts and search did their job up front, while the order-management and checkout work closed more of those sessions at the other end.

That's the part you can't put in a feature list: what it's like to hand a brand-defining migration to a team and watch the difficult, invisible parts simply work when it counts.

By the numbers

Year over year – new store (Mar–May 2026) vs the previous platform (Mar–May 2025), same season. 

Source: GA4 (pl.gant.com).

• Revenue per session: +51%
• Mobile conversion rate: +98% (roughly doubled)
• Mobile revenue: +129%
• Paid-search conversion rate: +210%
• Overall session conversion rate: +47%
• Purchases: +34%

Tech stack & integrations

• E-commerce Platform: Shopify (adapted global template)
• ERP Integration: Comarch ERP (near-real-time synchronization)
• Order Management System (OMS): Native Shopify multi-location architecture (4 locations), order routing managed by Comarch ERP
• Logistics & Returns Automation: Shopify Flow, InPost Quick Returns API
• Data Migration: Matrixify
• Marketing & Analytics: Emarsys (via Shopify App), GA4, Conversions API (CAPI)
• Privacy & Consent: OneTrust, Shopify Privacy API, Google Consent Mode v2