The client is a large retail company in the DIY and home improvement industry, operating a nationwide e-commerce platform that serves both professional customers and end consumers.

Their business model combines a highly decentralised product assortment with a single, centralised online storefront. This creates significant complexity on the digital side, as local product structures, categories, and content must all be supported within one scalable e-commerce experience.

Digital channels play a critical role for the client, not only as a sales platform, but as a practical tool that helps customers navigate a very broad and diverse product catalogue efficiently.

The client chose Shopify as a reliable and scalable commerce platform to support the next phase of their e-commerce development. It provided a stable foundation for future growth, while allowing custom extensions where retail scale and complexity required it.

The project focused on two major challenges.

The first was related to the front-end architecture. The existing e-commerce solution was being replaced with Shopify, requiring a complete front-end rebuild and the introduction of new features on top of an already complex catalogue structure. The store needed to support hundreds of collections organised across multiple hierarchical levels, going beyond Shopify’s standard configuration.

The second challenge was payments. The client relied on a local payment provider that is not supported out of the box by Shopify. This meant that a custom Shopify Payment App had to be built from scratch, fully compliant with Shopify’s strict security and certification requirements.

Both challenges required custom engineering and deep platform expertise, as standard Shopify solutions were not sufficient.

We approached the project in two parallel streams: front-end development and payment app development.

Front–end development

The front-end work included rebuilding the customer-facing experience and introducing new capabilities on top of Shopify.

To support the client’s complex catalogue, we designed and implemented a custom mega menu that accurately reflected the full hierarchy of collections.

As there was no backend support for managing such a structure, we implemented a front–end–driven solution using Shopify’s Storefront API. This required careful handling, as Storefront API data is only available client-side and cannot be pre-rendered in the same way as standard Liquid-based navigation.

Key elements of the solution included:

• Combining Shopify’s standard navigation for simpler menus with a Storefront API–powered mega menu
• Creating a custom data model using metaobjects and metafields to define parent–child relationships between collections
• Supporting four levels of navigation, exceeding Shopify’s native limitations
• Rendering the menu dynamically on the front end using React.js alongside Liquid, an uncommon but powerful approach in Shopify theming

We applied a similar custom approach to store filters. Due to the project structure and the use of metaobjects, existing Shopify filter apps could not be used. Instead, we built a bespoke filtering solution that allowed users to filter not only standard collection pages, but also pages generated from metaobjects.

Shopify Payment App development

In parallel, we independently developed a custom Shopify Payment App to integrate the store with the client’s preferred payment provider.

Before receiving official approval to develop a Shopify Payment App, we conducted a mini discovery phase, during which we:

• Defined the overall architecture
• Mapped communication flows between Shopify, the Payment App, and the payment provider
• Created detailed sequence diagrams to validate assumptions and scope

Once approval was granted, we moved quickly thanks to the upfront technical preparation. We built the Payment App entirely in line with Shopify’s payment app requirements.
The solution then passed an independent penetration test with no security issues identified.

We delivered a Shopify-based solution that supports:

• A highly scalable and intuitive navigation experience, despite extreme catalogue complexity
• Custom filtering capabilities tailored to non-standard Shopify data structures
• A secure, fully compliant custom payment integration, unavailable through Shopify’s native features

Beyond the technical delivery, our Shopify consulting expertise proved especially valuable. The client relied heavily on our recommendations and adopted many of the solutions we proposed, as they did not have in-house expertise for this level of Shopify customisation.

This level of trust and satisfaction led to continued collaboration, with our team remaining involved across multiple ongoing Shopify initiatives.

The project’s success is reflected in its stability, security, on-time delivery, and the long-term partnership that followed.