According to McKinsey, 9 out of 10 organizations are currently undergoing some form of digital transformation. Which raises an obvious question: What’s the other one doing?
If they’re working to maintain a legacy system, that costs an average of $40,000 every year—and that’s just the baseline for keeping the lights on. The real tax is in labor and opportunity cost: IT workers report losing an average of 17 hours per week maintaining aging platforms, which is less time to work on advancing new initiatives.
According to IMD, moving away from legacy technologies is one of today’s defining digital transformation strategies.
We’ll walk you through what it means to go from legacy to digital in retail, with success stories from commerce teams who’ve been there.
A legacy system is an outdated system, not necessarily in terms of age, but whether it costs more to maintain than it returns in value—in speed, stability, or in the customer experiences it can support.
A system built five years ago can already be legacy, and a system built 15 years ago might still be doing its job.
In commerce, legacy status tends to show up in four recognizable patterns:
Some of these systems don’t appear broken at first glance, but that’s the trap. They function, just not at the speed modern commerce demands.
McKinsey has a name for today’s shopper: “zero consumer.” These consumers have zero loyalty when a competitor makes things even slightly easier, and zero patience for the gap between what they experience online and what they find in-store.
Recent research finds that 65% of retailers’ current store technology can’t deliver the kind of experience today’s customers expect. Old, fragmented systems can prevent you from offering the smooth shopping experience customers expect, but it also hinders your ability to compete effectively in modern retail.
In a recent blog, Shopify Senior Engineer Patrick Joyce calls these compounding inefficiencies the “fragmentation tax,” and the bill arrives in four installments:
Before switching to Shopify, luxury jewellery brand Mejuri was contending with the difficulties of a legacy system.
“When you start looking under the hood, we were spending most of our time in building and maintaining third-party integrations, which come out of the box with a unified solution like Shopify,” says Rohit Nathany, chief digital officer at Mejuri.
For Mejuri, the shift to Shopify’s unified commerce model took less than nine months. Rohit called that timeline “insanely fast,” and the result was a fundamental reorientation of how the team spends its time.
There are real benefits to replacing a legacy system. . But ripping out and replacing your entire stack is a complex operation that can’t be done overnight.
Let’s look at the pros and cons.
Peter Sheppard Footwear has been around for over 40 years, with a deeply loyal customer base and stores in Sydney, Melbourne, and Brisbane. But on their legacy platform, even a simple update took 24 hours. After migrating to Shopify, they tripled their conversion rate and grew online revenue 30% season-on-season.
Fragmented systems create fragmented data, and fragmented data creates work. Nutrition Warehouse had 120 locations across Australia and New Zealand running on Adobe Commerce for ecommerce and a separate POS system that required full-day staff training sessions. After migrating to Shopify and Shopify POS, all 120 stores were onboarded in six months; staff training dropped from a full day to 15 minutes; and time spent on data consolidation fell 15%.
The family-run legacy shoe brand Giesswein started on Adobe Commerce. At first, the platform worked. But what it didn’t do was let the team grow. When they migrated to Shopify, average yearly sales grew 179%, and the brand expanded to five international stores in 12 languages and eight currencies—with zero downtime during peak sales periods.
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For our biggest product launch of the year, we saw a 200% increase in site visits and zero performance issues.
📚Read more: Avoid Digital Transformation Failure: 7 Mistakes Enterprise Commerce Leaders Make
These four approaches range from the least disruptive to the most complex.
You move the core engine to a modern cloud environment or a software-as-a-service (SaaS) provider, but you keep the underlying business logic and ERP connections exactly as they are.
This is the fastest way to get off your legacy system. That said, if you’re not careful with your choice of ecommerce platform, you’ll upgrade the interface, but still risk running on the same 10 years of broken integration debt.
In Queensland rainforests, strangler figs grow by wrapping themselves around an existing tree—slowly, over years—until the original tree is gone and the fig is standing on its own.
Martin Fowler borrowed this image to describe what’s now called the Strangler Fig Pattern: a way of migrating away from a monolithic system by incrementally replacing it, piece by piece, while the original keeps running underneath.
You identify specific functions, like your three-warehouse inventory logic, and rewrite them as independent microservices. You stay on the old system while slowly migrating functionality into a new, decoupled architecture.
Here, you swap your commerce core but keep the systems around it. You’re replacing the main commerce platform while keeping ERP, OMS, or other back-office systems in place.
You first solve the back]end complexity by introducing a middleware or integration-platform-as-a-service (iPaaS) layer. You have to funnel all your integrations into one source of truth first, and once the back end is tidy, the digital transformation of the storefront becomes much more plug-and-play.
Keep in mind, however, that this delays the visible transformation—the user interface—while you fix the plumbing.
This approach decouples the front end from the back end entirely. Your storefront and your back end become independent, connected via APIs but free to evolve separately. You can swap out any component without rebuilding the whole system.
This is high stakes, but it may be the best way to truly shed 10 years of technical debt in one go, like Westwing did. The European home and living brand had spent a decade building out a bespoke ecommerce platform in-house. The system was deeply customized and had become a major obstacle in the way of expanding into new markets.
So they ripped and replaced their entire commerce stack and moved to Shopify. On Shopify, they built a headless architecture that gave them a strong back end without sacrificing their branded storefront. They adapted Shopify Checkout to make the migration invisible to customers and built a single-store model they could replicate in every new market.
“We decided to move to Shopify as we believe it provides us with the most future-proof way to think about commerce,” says Usama Dar, CTO.
Westwing shows what’s possible with a clean break, but your path depends on how much weight your current system is carrying.
Use this logic to see if you should follow their lead or take a more incremental route:
If you answered no to the last question, that’s not surprising. For most enterprises, the Westwing way is too high-risk because of the sheer density of existing integrations.
The Strangler Fig Pattern is a helpful alternative, because it gives you the same modern end-state as a headless build, but without the “big bang” risk.
Gartner research highlights that a large proportion of digital initiatives struggle to meet their outcomes, and industry guidance increasingly favors incremental modernization patterns, like the Strangler Fig Pattern, because they limit risk exposure and allow quality lessons to inform each release cycle.
The Strangler Fig Pattern works in phases: as the old system gets smaller, the new one gets stronger.
In this stage you establish a shared, uncompromised picture of your current state.
You’re on track if: Every integration touching your commerce core is documented, and you can trace your last three incidents back to a root cause.
In this stage, you’re replacing one high-impact function that breaks most often or blocks growth.
Establish a clear before-and-after baseline tied to the function you’re replacing.
If it’s checkout, measure your checkout conversion rate, payment failure rate, and incident volume. If it’s inventory, monitor your oversell rate, manual stock adjustments, and reconciliation time.
You’re on track if: The function you replaced is generating fewer incidents and fewer manual interventions, and your checkout conversion rate is moving in the right direction.
You’ve decoupled one service, kept the business running, and ensured your team is comfortable with the new process. Now you repeat it, systematically, in order of impact.
You’re on track if: Time-to-ship has dropped, support ticket volume is down quarter on quarter, and new capabilities are going live faster.
Most digital transformation initiatives fail because of big-bang thinking. Companies often try to move 10 years of existing code and outdated technologies into a new system all at once.
The top reasons include:
Absolutely, more than ever. But the definition has shifted from going digital to building a digital ecosystem that can scale with customer expectations.
Read the full breakdown of the top digital transformation trends in retail in 2026.
McKinsey focuses on a holistic digital transformation journey that generally follows five pillars to move beyond legacy ways of working:
