As Shopify continues to evolve, more advanced pricing logic and promotional mechanics are moving out of themes and into platform-native extensions. Merchants with complex requirements can find themselves needing to go beyond the limits of standard discount rules, or needing a migrate from legacy solutions like Shopify Scripts.
I design and build custom Shopify Functions and Checkout UI Extensions that unlock advanced behaviour while remaining fast, reliable and fully compatible with Shopify’s roadmap. This work is typically aimed at merchants who need flexibility that simply isn’t possible with off-the-shelf apps alone.
Why Shopify Functions Matter Now
Many established Shopify stores still rely on Shopify Scripts, which are being deprecated in August 2026. For merchants using Scripts to power discounts, bundles, or checkout logic, this presents a significant risk but also an opportunity to modernise.
Shopify Functions are the long-term replacement: faster, safer and more deeply integrated into the platform. However, they require a very different way of thinking compared to Scripts or theme-based logic. Poorly implemented Functions can be hard to maintain, difficult to extend, or overly restrictive.
This is where a custom, well-architected approach makes a meaningful difference
What I Can Build For You
Custom Discount Logic
When Shopify’s built-in discounting tools aren’t quite enough, I can build Shopify Functions for advanced discount behaviour beyond Shopify’s native capabilities, including:
- Conditional discounts based on product combinations or conditions
- Tiered or logic-driven incentives
- Rules that respond to cart structure rather than simple thresholds
All logic is designed to be explicit, testable, and easy to evolve as requirements change.
Custom Product Bundling
Shopify’s app ecosystem, and even their own native solution, provide some great bundling solutions. But the additional subscriptions can quickly get expensive, or require you to shoehorn your ideas into a specific framework that doesn’t match your needs.
For merchants who want to run more unique bundle offers, I develop Functions that treat bundles as first-class pricing logic and allow for near-limitless creativity – so you can create compelling bundles for you customers, safe in the knowledge that discount logic will be applied securely, accurately and reliably.
Checkout UI Extensions
Where custom checkout messages or interactions are required, I build Checkout UI Extensions that integrate cleanly into Shopify’s checkout experience. These allow you to customise your checkout experience, helping to:
- Reinforce promotional logic
- Provide clarity around discounts, cross-sells and bundles
- Support a more transparent, confidence-building checkout experience
Extensions are built with performance, accessibility and Shopify’s strict checkout constraints in mind.
Migration from Shopify Scripts
With Shopify Scripts finally set to be retired in mid-2026, many clients still find themselves needing to migrate essential functions from Scripts to Functions.
Fortunately, the process for this doesn’t have to be intimidating. I can work with you to help:
- Audit your existing Script logic and intent
- Rebuild this functionality using Shopify Functions and, where necessary, Checkout Extensions
- Test & validate to make sure
The result is a future-proof setup that preserves flexibility without relying on unsupported or fragile solutions.
Reliability at Scale
These solutions are not theoretical. The Functions I’ve delivered process hundreds of thousands of executions per month, handling high daily run volumes without errors or degradation in performance.
This level of reliability is critical at checkout, where even minor issues can directly impact revenue and customer trust. As with my theme and performance work, everything is:
- Cleanly structured and well documented
- Fully tested before release
- Designed to fail safely and predictably
What You Can Expect
Clients working with me on Functions and checkout extensions can expect:
- Platform-native solutions aligned with Shopify’s roadmap
- Clear communication around any constraints and trade-offs
- Robust logic that survives real-world traffic and edge cases
- Code that is understandable, maintainable, and safe to extend
If your store relies on complex discounts, bundles, or legacy Script logic – or needs to prepare for Shopify Scripts deprecation – I can help you design and implement a solution that’s built to last
Need help with Shopify Functions?
Whether you need new custom functions or to migrate from Shopify Scripts, I can help. Hit the button below to book in a FREE 30-minute review where we can discuss your plans, and I’ll provide no-obligation thoughts & feedback.