Most generalist developers can build a Shopify store. Few of them can build one that converts well, performs well at sale-week traffic, and doesn't accumulate $800/month of unused apps. The gap shows up in revenue.
If you're commissioning an e-commerce build, here are six specific things to test for.
1. Real platform expertise
Shopify, WooCommerce, BigCommerce, and Magento are very different beasts. A "Shopify developer" should be able to talk fluently about Liquid, Sections 2.0, Online Store 2.0, theme architecture, and which apps they avoid and why. Vague answers mean theory, not practice.
Specifically ask: "What's your favourite Shopify section pattern, and why?" Real Shopify developers have an opinion. Generalists deflect.
2. Conversion focus, not just design
Beautiful is necessary; it's not sufficient. Ask:
- "Have you A/B tested anything you've built?"
- "What's the highest-converting layout for a collection page in your experience?"
- "How do you approach mobile checkout specifically?"
Developers who can't talk about conversion are designing visuals, not commerce.
3. Integration experience
Real Australian stores integrate with five to ten systems: Klaviyo, Recharge, Yotpo, Afterpay, Zip, Xero or MYOB, ShipStation or a 3PL, plus probably ERP. A developer who's done one or two of these has done some. A developer who's never done any will burn weeks learning on your money.
4. Performance discipline
The single most underrated skill in e-commerce development. Ask:
- "What Lighthouse score do you target on launch?" (95+ should be the answer)
- "How do you handle image optimisation?"
- "What apps do you avoid because they slow stores down?"
A slow store loses 7% of revenue per second of load time delay. Performance is a revenue metric, not an engineering one.
The fastest way to grow a Shopify store's revenue is usually to halve its page load time, not double its ad spend.
5. App stack discipline
Most stores I audit have 8–14 paid apps installed, half of which overlap or aren't used. A senior Shopify developer will remove apps as part of the engagement, not just add them. Ask: "When was the last time you talked a client out of an app they thought they wanted?"
Senior answer: a war story about replacing a $300/month app with 30 lines of Liquid. Generalist answer: "We use whatever the client wants."
6. Real references
For e-commerce especially, you want references whose stores are running today, with real revenue, who'll talk to you about the experience honestly. Ask: "Can I see two stores you launched in the last year and speak to one of those clients for 15 minutes?"
Anyone who can't produce that has either no clients or none willing to vouch for them. Both are problems.
The bottom line
E-commerce builds reward specialist experience. Test for platform fluency, conversion thinking, integration depth, performance discipline, app pragmatism, and real references. Skip any of those six and you'll find the gap in your revenue.
If you want three vetted Australian e-commerce developers on the same brief, FindDevs gets you those quotes. Free, in 24 hours.