Theme customization & AB testing for 7 and 8 figure Shopify brands to turn more visitors into customers and elevate your brand

Stop losing sales to a website that doesn't convert. Get expert development, design and data-driven testing that actually moves the needle.

Measurable revenue improvements through structured A/B testing

High quality Shopify development, design and CRO expertise

5 years experience working with 7 figure Shopify Plus brands

Book a free intro call

Why convertx

Many brands focus most of their efforts on acquisition and their business operations. Meanwhile, their website falls short due to lack of time or technical knowledge.
‍
Issues or missing features in the main buyer journey hurt customer’s ability to convert. 
As a result, you need to exert more effort to acquire customers and stay competitive. Every friction point is money left on the table. And the more you spend on ads without fixing the site, the more you're essentially paying to send traffic to a leaky bucket.

That's where I come in.

I handle frontend development, design and A/B testing on your store, so you can focus on acquisition and operations. Whether you need a specific feature built or want to systematically find conversion leaks, I'll bring that experience straight to you.

This way, your site improves together with your increasing traffic and fulfills user needs.

You'll regain time and focus to work on crucial areas, like backend operations and marketing. Less worrying about your website or spreading yourself thin trying to do it all.

Who is behind convertx?

I'm Fabian, frontend developer and CRO specialist with 5 years of Shopify Plus experience.

During that time I worked in-house for "Feelgrounds barefoot shoes", a Shopify Plus brand, supporting their growth from $2m to over $6m in annual revenue at their peak.

Starting with development and design, for the past 2 years I also established their structured A/B testing program. In the last calendar year alone, we ran 16 experiments with 5 winners, contributing to a ~27% measured revenue uplift.

Working in-house also helped me learn how to collaborate closely with marketing, copywriting, design, and product teams. This experience gave me a broad view into what makes a successful Shopify Plus brand, and helped me establish processes I now bring to every project.

What I do

Theme Customization

High quality development & design to build features that help customers buy

Design to code conversion

Custom sections & page components

Design & CRO audits

Checkout customization
(Shopify plus only)

Custom optimized carts

A/B Testing

Fix conversion leaks and test improvements to increase sales, backed by rigorous statistics

Customer research

Hypothesis development & test planning

Test implementation & QA

Statistical analysis & reporting

Actionable insights for iteration

What you need is not listed? Feel free to contact me and we’ll see if it’s possible:
Twitter: twitter.com/fabidoubleu or E-Mail: fabian@convertx.org

How it works

1

Intro call

We'll talk about your store, your goals, and figure out where the biggest opportunities are. No commitment, just clarity on what makes sense for you.
2

Get a clear plan

You'll receive a simple proposal with scope, timeline, and pricing. For A/B testing, we'll also outline the first test ideas based on your store's data.
3

Watch your store improve

We deliver what you need, with regular updates, quick iterations, and changes that translate into conversions.

Case studies

Feelgrounds - Theme customization

A selection of frontend work from almost 5 years with Feelgrounds: custom landing pages, menu optimizations, and pages speed optimization.
See how each project addressed specific conversion goals.
View case study

Feelgrounds - A/B Testing

5 winning tests out of 16, contributing to ~27% measurable revenue growth during their time at $6m+ revenue per year. Full breakdown with ROI analysis included.
View case study

Pricing and deliverables

Theme Customization

From €60 per hour or project-based
increasing soon
You have specific features, pages, or improvements you need built. You know what you want – you just need someone who can execute it well and fast.
What you get
Clean implementation, maintainable Liquid, CSS and JS code
Designs that convert, not just look good
Additional support, should issues arise
Up to two revisions for small changes if not satisfied
No dependency on page builders: native, future-proof Shopify code
Book a call

A/B Testing

Retainer or pay-per-test
You're getting traffic but not sure what's leaving money on the table. You want to replace guesswork with data: statistically validated changes that you can tie directly to revenue.
What you get
Full testing cycle:
research → hypothesis → implementation → analysis
Clear reports with actionable next steps
Strategic roadmap for continuous optimization
Statistical rigor, no decisions based on "gut feeling"
Book a call

Need help with something else?

If there's something else you need help with which is not exactly covered by my offers, don't hesitate to reach out. For example, consulting for your codebase, page design, choosing the right Shopify apps or CRO strategy.
Book a call

Not sure or have any questions? Check the FAQ below or feel free to contact me:
Twitter: twitter.com/fabidoubleu or E-Mail: fabian@convertx.org

Do you still have questions?

Why not hire a full-time Shopify developer/CRO marketer?

Cost-efficiency
‍Employing a full-time designer or developer can come with high costs, starting at around $50k annual salary with benefits on the very low end.

‍No tedious hiring process
‍Hiring a full-time employee can be very resource intensive. With me, you get high quality Shopify expertise fast, without the added cost.

‍Rapid start time
A typical onboarding process can take weeks, if not months. I’ve focused on making your onboarding process as simple as possible. And since I’ve seen many brands before, we are able to quickly integrate into your team and get to work fast.

How do you determine the exact pricing?

Theme Customization: Starts at €60/hour for smaller tasks. Larger projects get a fixed quote based on scope.

‍A/B Testing: Available as pay-per-test or monthly retainer. Based on your traffic, revenue and unique goals we'll determine a clear number that fits for your case.

What does your design include?

I focus on high converting web design, meaning layouts of sections, pages or page components, icons included.

This excludes creation of brand assets, infographics, or other graphic design tasks.

What does your Shopify development include?

I am focused on Shopify’s own coding language ‘Liquid’ and try to avoid using page builders or headless solutions when writing new code.

This leads to many benefits, including:

- Reliability as it’s a time-tested language
- Easy future support, backed and continuously improved by Shopify itself
- Less compatibility issues, because it’s native to Shopify

However, if your store uses page builders or runs on a headless solution, I'm still able to work with you, as I have experience in using both.

There may be instances where your codebase is not a fit for me to work with, and I’ll decide to not move forward from my end. In that case, I’ll refund you the full price you paid, no questions asked.

How does A/B testing work with you?

I handle the full testing cycle:

From customer research, identifying what to test, to implementing the experiment, running it until statistical significance, and delivering clear results with recommendations. You'll get a report for each test showing what we tested, what happened, and what to do next.

Tests typically run 4-8 weeks depending on how fast your traffic numbers allow them to finish.

How will you update me on progress?

For projects, I provide regular updates via messenger (usually Slack), as well as a shared project board if needed. You'll always know where things stand and can provide feedback throughout.

How quickly can I start?

Usually within a few days. Once we've had our initial call and aligned on scope, I can get started quickly.

For A/B testing, we'll need to set up tracking and do an initial customer analysis first if not already in place. This usually takes around 1 - 2 weeks. To avoid dead time, we'll launch a selection of prior successful tests in the meantime.  

Are there any refunds?

For Theme Customization: I focus on maintaining the highest quality and delivering any task to your satisfaction. I don't offer refunds, but I do offer up to two revisions in case you're not satisfied with the work. Additionally, I'll always provide support if something related to my feature breaks.

For A/B Testing: We set a clear ROI target upfront. If we don't hit it within the agreed number of tests, I continue working at no extra cost until we do. You only pay for results.