Currently available for select engagements

Hire a Shopify Functions developer for custom logic

Custom discounts, shipping and payment rules, and cart validation, built on Shopify Functions and running natively.

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15+

Years Experience

100+

Projects Delivered

Countries Served

$25M+

Revenue Enabled

Shopify Functions

Custom checkout logic without fragile workarounds

Shopify Functions let you change how discounts, shipping, payment methods and cart rules work, inside Shopify itself. They replace Shopify Scripts and many discount apps, and run fast at checkout.

I build Functions in Rust or JavaScript as custom apps for your store. For Scripts moves, see Scripts to Functions migration; for checkout UI, checkout extensibility developer.

What you get

What Functions can do

Custom discounts — tiered, bundle, customer-tag and product-specific discounts.
Shipping rules — hide, rename or reorder shipping methods by cart, customer or location.
Payment rules — show or hide payment methods based on cart value, country or customer.
Cart validation — block orders that break your rules, such as limits or restricted items.
B2B logic — customer-specific pricing and rules for wholesale buyers.
Replace apps — native logic instead of paying for several discount and shipping apps.

How it works

From first call to launch

Discovery call
A free 30-minute call to map your goals, stack and timeline, with an honest read on what it will take.
Fixed-scope proposal
A clear plan, timeline and fixed price. No hourly meters, no scope creep without your sign-off.
Build in weekly sprints
Work happens on staging you can click through anytime, with weekly demos and a shared punch list.
Launch & handover
QA across devices, analytics checks, documentation your team can use, and 30 days of post-launch support.

Why Omer

Why hire Omer

15+ years, 100+ projects across ecommerce, SaaS and enterprise, so senior judgment on every decision.
Senior Shopify Developer (ex-Integriti) with platform depth, not tutorial-level theme tweaks.
$25M+ in client revenue enabled through builds engineered to convert.
Operator background ran ecommerce operations for Nello, a drink brand, so commercial trade-offs shape the build.
Dubai-based, serving 6 countries with overlap across US, UK and Asia-Pacific hours.

FAQ

Questions, answered

Do I need Shopify Plus for Functions?

Many Functions work on all plans through a custom app. Some checkout features need Plus. I check what applies to your store first.

What language are Functions written in?

Usually Rust or JavaScript, compiled to WebAssembly, and deployed as a custom app.

Can you replace my Shopify Scripts?

Yes. Scripts are being retired, and moving to Functions is a core part of my work.

How much does it cost?

Project work is fixed-price against a defined scope, so you know the full cost before we start. The discovery call is always free.

How fast can you start?

Discovery calls happen within days; kickoff is usually 1-2 weeks out. If you have a hard launch date, say so on the first call and I will tell you plainly if it is achievable.

Shopify Experts & Services

Related services

Currently available for select engagements

Ready to get started?

The best way to explore working together is a quick conversation. Reach out through your preferred channel and let us discuss your project.

Start Your Project Email Omer