Shopify developer: what do they do, when do you need one, and how does Design by Karina help your ecommerce grow?

Introduction: why a Shopify developer is crucial for serious ecommerce growth

A Shopify developer doesn't focus on pretty pixels alone. The goal is to build a store that sells, scales and tells your brand story on every screen. Conversion optimization increases the sales of ecommerce stores, and that's exactly where a specialist's strength lies. In the Netherlands and Belgium, Shopify is a popular choice for fast-growing DTC brands in fashion, beauty and lifestyle. For a brand, the move to Shopify means going from a first sale to scalable omnichannel ecommerce. Many business owners start with a standard theme, but soon find they need a specialist to build a store that connects brand, UX and technology. Shopify developers improve conversion and revenue by looking beyond templates and colors. At Design by Karina, that's exactly what we do: strategy, design and development as one service.

In short

• A developer makes something work, a designer decides how it looks and works, and an agency combines strategy, design and development in one project.

• You need a developer when you want something your theme and the existing apps can't do, like a custom section, an integration or your own discount rules.

• Never hand over your password. A developer requests access with a collaborator account, and the store stays in your name.

Not sure whether you need a developer? Tell us in a free call what your store needs to do, and we'll tell you honestly whether that takes code.

If you want something in your store that the theme editor can't do, you naturally end up with the question: do I need a Shopify developer? And right after that come the other questions. What exactly does a developer do, what's the difference with a designer or an agency, what does it cost, and how do you know someone is good before you give them access to your store?

In our work, we decide what the store needs to say before we decide how it looks. A developer then makes sure it really works, also when you want more than your theme can do out of the box. That's valuable work, but it isn't always needed. So I'll start with what you can do yourself, and then get to what a developer does for you, what it costs, how to brief and check someone, and why your store should always stay yours.

What is a Shopify developer?

A Shopify developer is a web developer who specializes in Shopify's platform. A general web developer can build any website. A Shopify developer also knows the parts only Shopify has: the Liquid template language, how Shopify themes are built, apps, and the ways to customize Shopify's own logic.

The work roughly falls into four parts:

• Themes. Customizing an existing theme or building a custom one, with Liquid, HTML, CSS and JavaScript. Think of a custom section, a different product page or a menu that works with your categories.

• Apps. Building a custom app for something only your store needs, or making existing apps work well together.

• Integrations. Getting your store to talk to your accounting, your warehouse, an ERP system or a marketplace.

• Maintenance. Fixing bugs, improving speed, cleaning up code that apps left behind, and keeping your theme up to date.

Developers who work for clients usually have a Shopify Partner account. With it, they request access to your store, or build a new store that they then transfer to you. Further down, you'll read how to do that safely.

Developer, designer or agency: who does what?

On freelancer and agency websites, the titles get mixed up. That's why it helps to look at what someone does, not at what they call themselves.

Some designers also build, and some developers also design. So don't just ask about the title, ask what exactly someone is going to do, and what not.

Liquid, themes, apps and Shopify Functions, in plain words

You don't need to read code to hire a good developer. It does help to know the words you'll come across in a quote.

Liquid and Shopify themes

According to Shopify, a theme controls the organization, features and style of your store. Themes use Liquid to generate the HTML of your pages: Liquid fetches your product name, price, variants and photos and puts them in the right place. Pages are made of sections, reusable pieces of content you add, remove and move around, with blocks inside them, like a heading or a button. The basics of Shopify theme development usually take a few months to learn. For example: freeCodeCamp offers free courses in HTML, CSS and JavaScript as a stepping stone to working with Liquid and Shopify themes.

That's the most important thing to know right away: a developer can build a new section that you then use and fill yourself in the theme editor. So ask for a section you can edit yourself, not a page that's locked in code. How to choose the right theme is in How do you choose the right Shopify theme?

Apps

Apps add features that aren't in Shopify itself, like reviews, subscriptions or a loyalty program. Usually you install an existing app from the Shopify App Store. A developer can also build a custom app, for something only your store needs; custom Shopify apps like that often call for knowledge of modern JavaScript frameworks alongside the app logic, to build specific features well. Every app is code that runs along with your store, so more apps isn't always better. Sometimes a custom section in your theme is lighter than an app.

Shopify Functions

With Shopify Functions, you customize Shopify's own logic while a customer checks out: discounts, shipping options, which payment methods someone sees, and validations in the cart and checkout. Think of "free shipping, except for this one product group" or "this payment method only above a certain amount".

Good to know: App Store apps that use Functions work on every Shopify plan. According to Shopify, a custom app with Functions only works on Shopify Plus. So if you want your own rules on Basic, Grow or Advanced, look for an existing app first.

The checkout

The checkout belongs to Shopify, and you can only customize it to a limited extent. According to Shopify, custom elements in the information, shipping and payment steps are only available on Shopify Plus. If someone promises to completely rebuild your checkout on Basic, ask how.

Headless

Headless means the front of your store is built separately from Shopify, with its own framework, and Shopify only handles the products, the checkout and the orders. Shopify has Hydrogen for this, its own headless toolkit. Headless commerce is gaining popularity in ecommerce, but it isn't automatically the best choice for every brand. It gives you a lot of freedom in your front end and your choice of technology, and that front end is fully custom-made, but you lose the theme editor and need a developer for every change. For a brand that wants to keep its store up to date itself, that freedom rarely outweighs the downside.

When is the theme editor enough?

More often than you'd think. Modern Shopify themes are built on sections and blocks, and with them you can already do a lot without code:

• Change copy, photos and videos, on every page.

• Add, remove and move sections and blocks, like reviews, FAQs or an image with text.

• Set colors, fonts and buttons for your whole store.

• Edit menus and navigation.

• Create a separate template for a group of products, with a different layout.

• Add your own fields with metafields, like material or care, and show them in your theme.

• Translate or edit your theme's text, like "Sold out".

Not sure whether something can be done without code? Duplicate your theme and try it in the copy first. Your live store keeps selling, and you'll see right away where the limit is.

When do you need a Shopify developer?

A developer is worth it when you run into one of these things:

• A section your theme doesn't have and that no app does well, like a product comparison or size advice placed right at the size choice. Optimizing product pages can increase conversion.

• Product options that go beyond variants, like engraving, made-to-measure or a configurator.

• An integration with your accounting, warehouse or ERP for which no good app exists.

• A slow store because of apps and code that have piled up over time; then Core Web Vitals are an important benchmark for loading speed, optimization and performance.

• Your own rules for discounts, shipping or payment that Shopify doesn't support by default.

• A migration with lots of products, customers and old web addresses that need to redirect.

• A theme with custom code that you want to update. Shopify recommends keeping a copy of code you've changed yourself, and a developer knows what needs to happen with it during an update.

At VYOLA, a Belgian atelier for made-to-measure body jewelry, the product page had to sell a fit, not just a size. Size guidance and a considered ordering flow sit right where the doubt comes up. Something like that starts with design: first decide what the customer needs to know at that moment, and only then how to build it.

If it's about speed or getting found, also read Shopify SEO. Part of what's in there, you can do yourself.

Good to know in the Netherlands

VAT and hourly rates. Knab's average rates exclude VAT (btw, the Dutch VAT). Always ask for both amounts in a quote, so you know what you'll really pay.

Check the KVK. A freelancer or agency in the Netherlands is listed in the trade register of the KVK, the Dutch Chamber of Commerce. Check that the name and KVK number on the quote match.

Who owns the code? In the Netherlands, the copyright on code someone writes for you in principle belongs to the maker, even if you pay for it. A transfer has to be in writing, in a deed. Put in your quote or agreement that you may keep using and changing the code, also through someone else. This isn't legal advice: if in doubt, ask a lawyer.

Your customer data. Anyone with access to your Shopify admin can often also see orders and customer data. Only give the permissions that are needed, and agree on what someone may do with that data.

In Belgium: there, you look up a freelancer or agency in the Crossroads Bank for Enterprises (KBO) instead of the KVK.

Already have a quote from a developer or agency? Then go through the checklist below before you sign.

What does a Shopify developer cost?

In the Netherlands, a freelance web developer charges €73 an hour on average, excluding VAT. That's in the Knab Zzp Uurtarievenboekje 2026, Knab's survey of more than 20,000 freelancers. It doesn't list a separate rate for Shopify developers, so use these figures as a guide.

Source: Knab, Zzp Uurtarievenboekje 2026, via bieb.knab.nl, checked in November 2026.

An example, not a quote. If a custom section takes eight hours of work, at €73 an hour you pay about €584 excluding VAT. Add testing, a few feedback rounds and sometimes an app. Agencies usually work with a project price instead of hours. In the long run, a good developer can actually save you money by avoiding mistakes, workarounds and inefficient solutions. That's not automatically more expensive: look at exactly what's included, what the scope is, and whether strategy and design are part of it. What a complete Shopify store costs is in What does a Shopify store cost?, and how freelance rates work for a website without a store in What does it cost to have a website made?

How to brief a Shopify developer

A good brief saves hours, and so money. Write these things down before you ask anyone for a quote:

1. What you want, and why. "Customers are unsure about their size, so the size advice needs to sit at the size choice" helps a developer more than "make a pop-up".

2. An example. A screenshot of a store where it works well, with what you like about it.

3. Your theme and your apps. Which theme, which version, and which apps are running.

4. What mustn't change. Your checkout, your translations, an integration that works well now.

5. How it should work on a phone. That's often where your customers look first.

6. Who maintains it afterwards. Want to be able to change it yourself in the theme editor? Say so up front.

7. How you'll test. In a copy of your theme, before it goes live.

8. Your timeline and your budget. Even if it's a rough estimate.

How to check a Shopify developer

• Look at live stores on your phone. Ask what exactly they did there: the design, the code or both.

• Ask what they would do without code. A good developer tells you when something can also be done with the theme editor or an existing app.

• Ask how they work. In a copy of your theme, with version control through Git, and only live after your approval.

• Ask for a written quote. With what is and isn't included, and what happens after delivery.

• Look in the Shopify Partner Directory. There you'll find partners listed by Shopify itself, with their services and examples.

• Also use freelance platforms and marketplaces. There you'll find Shopify developers, and verified profiles can give you extra confidence.

And a few things to watch out for: someone asks for your password, wants to put the store in their own name, installs apps without asking, or edits code in your live theme without a copy.

Give access with a collaborator account, not your password

You never give a developer your own password. With it, someone can do everything, including things you don't want, and you can't see who did what. Shopify has collaborator accounts for this. Here's how it works:

1. The developer requests access to your store through their own Shopify Partner account.

2. For that, you give them a four-digit code that you create in your admin. If you create a new code, the old ones stop working.

3. You accept the request and choose which permissions they get. Only give what the job needs, like access to your themes.

4. Collaborators don't count towards the number of users on your plan.

5. When the job is done, you remove the account. That's permanent.

According to Shopify, there are two things a collaborator can't do: become the owner of your store, and use the Shopify POS app.

Who owns your store?

It sounds obvious, but always check it: your store should be in your name, not your developer's or agency's.

• The owner account is in your name and your email address, with your payment method for the plan.

• If someone builds a new store for you, that often happens in a development store in the developer's Partner account. That store is transferred to you as soon as it goes live. After that, you're the owner, and it no longer belongs to the developer's organization.

• Your domain name is in your name, with a provider where you can log in yourself.

• Apps and a paid theme run through your account. A paid theme is licensed for the store where you buy it.

• Your code has been transferred to you in writing, or you have a clear license to use and change it.

• A copy of your theme is something you keep yourself, before and after every big change.

Yourself, a freelance developer or an agency?

• Yourself, with the theme editor. For copy, photos, sections and the day-to-day changes. It costs you time, not an hourly rate.

• A freelance Shopify developer. For a clear technical job where you already know what it needs to be: a section, an integration, a speed problem. You pay per hour or per job, and you make the decisions about your brand yourself.

• An agency that starts with strategy. When your store needs to be designed and built around your brand, and design and development have to fit together. You pay more in one go, and you get a store that's right from the start.

Code doesn't solve what your store needs to say

I've seen €15,000 websites that don't convert.

Good code makes your store fast and reliable. But if it isn't clear what the store needs to say, and to whom, even the most beautiful section won't change that. That's why our work starts with your brand and your customers, and only then with the code.

Who we are and what we do

We're Design by Karina, a boutique Shopify agency in Rotterdam. We design and build strategy-led Shopify stores for ambitious fashion, beauty and lifestyle brands. Combining brand strategy, UX and thoughtful design, we create shopping experiences that turn what makes you different into a reason to choose you.

Ecommerce strategy

Who are your customers, what do they want to know, and what helps them choose your brand? We define the positioning, the customer journey and the structure of your store before design begins.

Shopify design

A store should feel unmistakably yours and work intuitively. We design Shopify stores around your brand, from the homepage to the product pages, and always mobile first.

Shopify development and migration

From a custom Shopify theme to migrating an existing store. Coming from WooCommerce or another platform? We help you with a clear plan for your store, your content and your customers' experience.

Conversion and retention

What customers need to see, understand and feel before they choose, from product pages to the emails after the sale.

Growth after launch

We look at how real visitors use your store and improve, step by step, what brings in the most.

Brand Sites

For coaches, creative studios and service businesses with something to say.

Why business owners choose us

• Strategy before pixels. Before we open a design file, we want to understand who buys from you and what those people need to see first.

• A background in product design. Before starting Design by Karina, I worked in product design at Uber, where I helped shape payment experiences for drivers.

• Fewer projects, more care. We work on a limited number of projects at a time, so I'm closely involved in every project.

• We say it straight. If a free theme and a few good tweaks are enough for your store, we'll tell you.

• Launch is the starting line. After launch, we keep improving your store based on what real visitors do, so we can also deliver faster on speed, user experience and conversion; faster websites improve user experience and conversion.

See our work in projects.

What does it cost to have your Shopify store designed and built?

If your store needs custom code, like a custom section or an integration, you'll see it in your quote, with the reason. If you're moving to Shopify from another platform, the migration comes as an add-on in your quote.

Shopify developer: the short version

A Shopify developer builds what your theme and the existing apps can't: custom sections, apps, integrations and your own rules with Shopify Functions. For copy, photos, sections and menus you have the theme editor, and it gets you further than you'd think. In the Netherlands, a freelance web developer costs €73 an hour on average, excluding VAT. Brief with the why included, check live work on your phone, give access with a collaborator account instead of your password, and make sure your store, your domain and your code are in your name.

What we see with clients

When business owners come to us asking for a developer, it's often about one thing their theme doesn't seem able to do. Sometimes code is the answer. Often the theme turns out to be able to do it, but the information is in the wrong place, or a step that helps customers choose is missing. That's why we first look at what the store needs to say, and only then at the code.

Sources

• Shopify.dev, theme architecture: themes, Liquid, sections, blocks and JSON templates, https://shopify.dev/docs/storefronts/themes/architecture (checked in November 2026)

• Shopify.dev, Shopify Functions and the plan requirements for custom apps, https://shopify.dev/docs/api/functions (checked in November 2026)

• Shopify.dev, Checkout UI extensions, https://shopify.dev/docs/api/checkout-ui-extensions (checked in November 2026)

• Shopify.dev, Hydrogen, https://shopify.dev/docs/storefronts/headless/hydrogen (checked in November 2026)

• Shopify Help Center, collaborator accounts, https://help.shopify.com/en/manual/your-account/staff-accounts/collaborator-accounts (checked in November 2026)

• Shopify Help Center, transferring stores to a client, https://help.shopify.com/en/partners/manage-clients-stores/development-stores/transfer-stores (checked in November 2026)

• Shopify Partner Directory, https://www.shopify.com/partners/directory (checked in November 2026)

• Knab, What does a freelance web developer earn in 2026?, https://bieb.knab.nl/ondernemen/wat-verdient-een-web-developer-zzp-bekijk-uurtarief-en-winst (checked in November 2026)

• Knab, What does a freelance designer earn?, https://bieb.knab.nl/ondernemen/wat-verdient-een-designer-zzp-bekijk-uurtarief-en-winst (checked in November 2026)

• Dirkzwager advocaten, copyright on software (transfer by deed), https://www.dirkzwager.nl/kennis/artikelen/auteursrecht-op-software, and IT contracts: intellectual property (rights in principle with the maker), https://www.dirkzwager.nl/kennis/artikelen/it-contracten-deel-14-intellectuele-eigendom (checked in November 2026)