Shopify, WooCommerce and Magento Customisation
Custom development, plugin work and theme changes on Shopify, WooCommerce or Magento when the platform is right but an off-the-shelf theme or app cannot carry a rule your business runs on. Built and run by GullySystem.
When the Platform Is Right but the Theme or App Is Not
You chose Shopify, WooCommerce or Magento because it is the sensible platform for the size of your business, but a specific rule, a bundle price, a subscription combined with a one-time item, a custom shipping calculation, does not fit any available app. Stacking several apps together to approximate it slows checkout and makes support harder every time one of those apps updates.
What Platform Customisation Covers
Theme and Checkout Customisation
Page layouts, product options and checkout fields built specifically for how you sell, beyond what a purchased theme offers.
Custom Plugin and App Development
A plugin or app built for a rule specific to your business, when no existing app in the platform's store does the job.
Third-Party API Integration
Connecting the platform to your accounting, courier, payment or CRM systems where a ready plugin does not exist or does not do enough.
Performance and App Conflict Resolution
Diagnosing why several installed apps are slowing checkout or conflicting with each other, and rebuilding the affected logic directly.
An Example: Bundles and Subscriptions on the Same Checkout
A supplements brand on WooCommerce wants to sell a starter bundle at a bundle price and let the same customer add a monthly subscription for one item in it, and no combination of installed plugins handles both together without errors at checkout. Custom development on top of the existing store adds the bundle-and-subscription logic directly, so the brand keeps its existing theme, catalogue and customer accounts without moving to a different platform.
What Shapes the Cost and Timeline of Platform Customisation
- How many of your current apps or plugins conflict with the change you need
- Whether the work is a theme change, a new plugin, or a checkout rebuild
- How much custom logic depends on data outside the platform, such as your ERP
- Whether the platform's own update cycle affects how the customisation is maintained
- Testing across the specific payment and shipping methods you currently use
Frequently asked questions
How do we know if we need customisation instead of switching platforms?
If your current platform handles most of your catalogue and checkout well and only a specific rule does not fit, customisation is faster and cheaper than moving. Switching platforms is worth considering only when several core rules keep failing, not just one.
What makes platform customisation cost more in one case than another?
How deeply the change touches checkout and payment logic, and how many existing apps it has to work alongside without breaking them, drive the cost more than the choice of platform itself.
What usually takes the longest?
Testing the change against your live payment methods, shipping rules and any apps you already depend on, because a working store cannot simply be taken offline to test.
Will this affect the apps and integrations we already have installed?
We test alongside your existing apps and flag any conflict before building rather than after. Where a conflict cannot be resolved, we say so plainly.
Who owns the custom code once it is built?
You do, and it is documented so it survives a theme or app update on your end, or a different developer maintaining it later.
What do we need from you before this starts?
Admin access to your store, a list of currently installed apps and plugins, and a clear written description of the rule that is not working today.
Tell us what you need.
Send a short brief and one of our engineers will come back to you — usually the same day.
- No obligation
- We reply the same working day
- Your details stay private