When most people think about building an online store, they think about how it looks. The design, the product photos, the fonts. What they don't think about — until it causes problems — is how it's built.

The underlying structure of your ecommerce store, what's technically called its architecture, determines how fast it runs, how easy it is to update, how well it scales, and ultimately how much it costs to maintain over time. Get it right from the start and everything flows. Get it wrong and you end up rebuilding.

Here's a plain-English breakdown of the main approaches, and how to know which one fits your business.

The building blocks of any online store

Every ecommerce store — regardless of how it's built — has three underlying layers doing the work:

The first is what your customers see and interact with: your design, navigation, product pages, buttons, images. The second is the logic running underneath: inventory, pricing, checkout, promotions. The third is your data: customer records, order history, product information, all stored and retrieved behind the scenes.

Different architectures handle these three layers in different ways. Some keep them locked together. Others separate them for more flexibility.

The four main approaches

1. Monolithic (all-in-one)

This is the traditional approach — and for most independent retailers, it's the right one. Everything is integrated: design, logic, and data all live within the one platform. Shopify is a monolithic platform, and it's the one I build on most.

The benefits are significant: faster to launch, lower technical overhead, less to maintain, and no need for expensive developers just to make everyday changes. For a furniture brand, a cycling store, or an artist selling their work online, a well-configured Shopify build covers everything you need without the complexity you don't.

The limitation is flexibility — but for most stores at this stage, that limitation doesn't actually matter yet.

2. Headless

A headless setup separates the front end (what customers see) from the back end (the data and logic). The two talk to each other via APIs. This gives developers more control over the customer experience and allows for faster front-end changes without touching the back end.

This is a legitimate approach for brands running multiple storefronts, complex personalisation, or highly custom experiences. But it comes with meaningful trade-offs: more technical complexity, higher development cost, and more to maintain. Unless you have specific requirements that a standard Shopify build genuinely can't meet, headless is often overkill.

3. Modular

A modular approach breaks specific functions into swappable, pre-built components that can be added, replaced, or upgraded independently. Think of it as building with purpose-built blocks rather than a single integrated system.

This sits between monolithic and fully custom. Shopify's ecosystem of apps is effectively a modular layer on top of a monolithic core — which is one reason it works so well. You can add a loyalty program, a review system, or a subscription tool without rebuilding anything from scratch.

4. Microservices

The most granular approach, where every single function of your store runs as an independent component. Maximum flexibility, maximum technical investment. This is the domain of large enterprise retailers with in-house engineering teams. Not relevant for the clients I work with, and worth mentioning only so you know when someone's overselling you.

What this actually means for your store

If you're running a homewares brand, a bicycle shop, or selling artwork and prints — a well-built Shopify store on the right theme, with the right apps configured properly, will outperform a poorly implemented headless build every time. Architecture only matters when your current setup is genuinely holding you back.

The questions worth asking are:

• Are you losing sales because your store is slow or hard to update?
• Do simple changes require a developer every time?
• Are you selling across multiple channels — retail, wholesale, online — and struggling to keep everything aligned?
• Is your product catalogue complex enough that standard templates genuinely don't cut it?

If the answer to most of those is no, you don't need a more complex architecture. You need a better implementation of what you already have.

If the answer to several is yes, it's worth a conversation about whether your current setup is actually the right fit.

The bottom line

The best ecommerce architecture is the simplest one that reliably does what your business needs. For most independent retailers — whether you're selling handcrafted furniture, cycling gear, or original artwork — that's a properly built Shopify store, configured for your specific products and customers, without unnecessary complexity layered on top.

That's exactly what I build. If you're unsure whether your current store is set up the right way, I'm happy to take a look.