Facade of Kattenberg 118 in Borgerhout, Antwerp
No agency. Just someone who's worked the shop floor.
Jonas — Shopify developer and strategist at Kattenberg 118

I'm Jonas, 40. For fifteen years I ran two jewellery stores and a sizeable webshop — at its peak, a team of twenty. I know what it's like when systems fail mid-sale, when your stock counts are wrong, and when agencies sell you a solution without ever understanding how your business actually works.

So I learned to code and went all-in on Shopify. I'm not the consultant who advises from a distance — I show up at your shop, roll up my sleeves and build it alongside you. I work exclusively with one client at a time, so your business gets the full focus it deserves.

Services

  • Moving to Shopify — Development & Build

    On an ageing system or starting from scratch? I handle the full transition — from safely migrating your products to building a store that converts. By day one, you'll understand exactly why Shopify dominates the market.

  • The Ecosystem — Marketing, Loyalty & Reviews

    A webshop is more than a catalogue. I implement and configure the full stack: advanced email marketing in Klaviyo, loyalty and review programmes via Okendo or Loyalty Lion. Everything connected and working together.

  • Shopify POS & Custom Apps

    I install Shopify POS on-site, configure the hardware and train your team. Got a workflow that doesn't exist out of the box? I'll build the custom app that makes your software fit your business — not the other way around.

How I work

  • One client
    at a time

    Moving to a new platform is a big deal. That's why I'm 100% yours for the duration — 1, 3 or 6 months. No split focus, no competing priorities. One project, full attention.

  • Budget-
    conscious

    I used to pay those software licences myself. I have no financial interest in expensive platforms. If something can be done cheaper or free, we do it that way. I protect your budget like it's my own money.

  • On-site,
    not remote

    I typically spend 1–2 days a week at your location. I need to see how your team actually works — the small frictions at the register, the warehouse workarounds — before I can build exactly the right system.

The approach

1

Floor-level analysis

We start in your shop. I shadow your staff to find where things actually break down. What I see becomes the blueprint in Shopify.

2

The Blueprint

I draw up a migration plan and the marketing stack you need. You get a fixed proposal: period, investment, no surprises.

3

Build & Integration

I build the platform and connect all systems (email, reviews, POS). Weekly on-site visits to test progress and course-correct as we go.

4

Training & Go-Live

I train you and your team in the shop. We go live when everyone — from owner to Saturday staff — is confident with the system.

5

Handover & Independence

At the end of the period, everything runs without me. That's the goal. Your team has the knowledge to keep growing on their own.

6

Aftercare

I move on to my next client, but I stay available for questions and technical issues. You have a stable, profitable platform built to last.

Work

A selection of completed projects.

Development & Build

Our House

Sector: Books

Katrien called on a Wednesday with a problem. She'd co-written a book being launched on Sunday — but had no webshop. Could I build a Shopify store in four days? Wednesday morning we had coffee, by Wednesday afternoon the domain was live, and Friday afternoon we went public. Books have since shipped to 11 countries, including Australia and Japan.

inourhouse.be
  • Shopify
  • Payments
  • Sendcloud
POS & Custom

De Wereld van Smaken

Sector: Popup shop

For the Steiner school my kids attend, I handled the full technical setup of a new Shopify store — including migration from an old platform and a live popup-shop for special events. Products, payment providers, order processing, supplier communication: all taken care of. A fully managed platform, start to finish.

dewereldvansmaken.be
  • Shopify
  • Shopify POS
  • Payments
Development & Build

Treen.nu

Sector: Consulting

Joris had needed a website for years but never got around to it. We sat down and figured out what he actually needed — and it turned out to be something minimal. No complicated CMS, just a clean static one-pager. The photos still need taking. :-)

treen.nu
  • Next.js

Own Applications

Built out of necessity.

  • RepairManager app icon

    Repair Manager

    Many retailers hesitate to move to Shopify because their specific workflows — like repairs — aren't in the standard software. So I built RepairManager: a full repair management system that integrates seamlessly with Shopify and Shopify POS.

    More info
  • Sendcloud Connector app icon

    Sendcloud Connector

    For inourhouse.be and my own stores, I solved the biggest shipping problem: incorrect costs at checkout. This connector pulls real-time shipping rates from Sendcloud so customers never overpay or underpay.

    More info
  • CreditClub app icon

    CreditClub

    Build a loyalty programme that integrates natively with Shopify Store Credit. Automatically reward customers on every purchase and drive more spending with configurable loyalty tiers. 100% native, 100% automatic.

    More info

What clients say

“We spoke for the first time on a Wednesday, and we were live on Friday. I never thought that was possible. Jonas handled everything — the domain, the payments — while I just focused on presenting my book. We now sell to 11 countries. I wouldn't have dared to dream that.”

— Katrien, Our House

“As a school project, setting up a webshop felt like a big step. Jonas took everything off our hands: the tech, the products, the payments, even the communication with suppliers. During the world market everything ran perfectly. The kids and parents were impressed.”

— De Kleine Wereldburger, Antwerp

“I'd needed a website for years but kept putting it off. Jonas asked the right questions, thought carefully about what I actually needed, and built exactly that — nothing more, nothing less. Fast, clear and no fuss.”

— Joris, Treen.nu

FAQ

About the migration & the platform

Why Shopify and not another platform?

Because you want to sell, not spend your time tinkering with your website. Shopify is the global gold standard: extremely secure, blazing fast, and its app ecosystem for marketing, reviews and loyalty is unmatched. You're freed from technical updates and server headaches — Shopify takes all of that off your plate.

Is migration risky for my existing data?

Migration is always a big moment, but with the right approach, nothing gets lost. I have extensive experience moving product catalogues, customer data and order history from Lightspeed, Magento or WordPress to Shopify. We test everything thoroughly before the final switch.

Can I keep my current hardware with Shopify POS?

Often yes — barcode scanners, cash drawers. For the terminal itself we look for the most budget-friendly and reliable option. If new hardware is genuinely needed, I'll advise you objectively on what's necessary. I have no interest in selling hardware; I have an interest in a system that never crashes.

My staff aren't very technical. Can they handle Shopify?

That's exactly why I spend 1–2 days a week on-site. I'm not just building the system — I'm training your team where they work. Shopify POS is intuitive. If they can use a smartphone, they can use this. I'll put together a guide tailored to your specific shop workflow.

Can my customers still use their old gift cards or loyalty points?

Yes. During the migration phase we figure out how to safely transfer any outstanding balances from your old system to Shopify. The last thing we want is a frustrated regular customer at the till. We make sure the handover is clean.

About costs & budget

Shopify apps and licences aren't cheap. How do you keep costs under control?

It's my speciality. I spent years paying those invoices myself, and I know every euro counts. I have no commercial interest in software partners. If a solution can be done for free or cheaper, that's what we do. I treat your budget like it's my own money.

Do you work with fixed prices or an hourly rate?

Fixed project prices only, for the agreed period (1, 3 or 6 months). You know exactly what you're committing to upfront. No “time and materials” surprises at the end of the month. Transparency is the foundation of a good working relationship.

Shopify takes a cut of revenue. Is it worth it?

That percentage buys you peace of mind — no hosting costs, no security patches, no server maintenance. And Shopify Checkout has the highest conversion rate in the market. You pay a small fee, but you keep more at the bottom line through fewer IT headaches and more sales.

About working on-site

Why come 1–2 days a week to my location?

Software has to work on the shop floor, not just in a test environment. Being physically present means I see how you and your team really work — the small irritations at the register, the storeroom workarounds that nobody mentions in a call. That's what I use to build a system that fits precisely.

What do you do on the days you're not on-site?

I work from my studio at Kattenberg 118: writing code for custom apps, designing your shop, building out flows in Klaviyo. Because I have no other clients at that point, development moves fast.

What happens on Go-Live day?

I'm physically there when you switch off the old system and switch on the new one. No panic calls — direct support at the counter, from the very first transaction until you and your team have full confidence.

About expertise & custom apps

Can you also set up my full marketing and loyalty programme?

Absolutely. A good shop is just the start. I implement and configure everything: advanced email marketing in Klaviyo, review systems, loyalty programmes like Okendo or Loyalty Lion. All systems connected and talking to each other, so you get a 360-degree view of your customer.

What if I have a workflow that Shopify doesn't support out of the box?

We build it. That's exactly why I developed my own apps like RepairManager. I always look for an existing solution first. If there isn't one, I write the code for a custom app that works seamlessly within your Shopify environment.

Can you integrate with my accounting software or ERP?

In most cases there's a direct integration or API solution available. I check this during the initial analysis phase. If the connector doesn't exist, I can often build one to your specifications.

Do you have experience with international sales and VAT?

Yes. Via Shopify Markets we set up your shop so that languages, currencies and VAT rates are automatically correct for every country you sell to. Your accountant will be happy too.

About the end of the project

Why work with one client at a time?

Because complex e-commerce isn't a side project. When I'm working for you, I'm thinking about your business constantly. That focus is my biggest product. At an agency you're a line in a schedule; with me you're the only one on it.

Will I be dependent on you after the project?

No — and that's the whole point. By the end of the period your team is trained and everything runs independently. I document everything I've built so you're never locked in. I'm still available for urgent questions or technical issues, of course.

What if we're not finished by the end of the agreed period?

We set the timeline based on a realistic estimate. If scope changes during the project — say you want to add extra features — we discuss it early and decide together whether to extend the period.

Do you keep up with the latest Shopify updates?

It's genuinely my favourite part of the job. I follow every development closely. During our project you'll benefit directly from the latest Shopify features, often before larger agencies have even heard of them.

Ready to make the move to Shopify?

Want to see how Shopify can strengthen your physical store and webshop without drowning in expensive licences?
Let's meet at your location or at Kattenberg 118.

contact@kattenberg118.be

Build on experience, not promises.

Shopify is the engine — but the setup is what determines your success. Want a platform that's technically solid, marketing-ready, and within your budget?

I work exclusively with one client at a time. Reach out early to reserve a period for your migration.

Ready to leave your old systems behind and move to a platform that actually works? Let's build it together.

Facade of Kattenberg 118 in Borgerhout, Antwerp