Most Shopify app work fails on the invisible platform rules — review, billing, webhooks, GDPR — not the features. Here's how to pick a company that actually ships one that survives.
Before you shortlist anyone, settle one fork: are you building a custom app for your own store, or a public app you list on the Shopify App Store for other merchants to install? They share a platform and almost nothing else. A custom app solves one store's problem against data and a theme you control. A public app is a software product that has to install cleanly on stores you'll never see, pass Shopify's review, bill money reliably, and support strangers. Hire the wrong kind of company for the job and you'll pay for it twice.
A good Shopify app development company is judged on the parts a demo never shows: surviving App Store review, billing through Shopify's Billing API, processing webhooks that arrive late or twice, keeping the storefront fast, and handling GDPR. This is the buyer's guide to telling a shop that ships one from a template mill that hands you a working demo and a support ticket. If you mainly want a price, we broke that down in how much a Shopify app costs to build; this piece is about who you trust to build it.
The distinction decides everything downstream, including who you should hire.
| Custom / private app | Public App Store app | |
|---|---|---|
| Built for | One store or organisation | Any store that installs it |
| App Store review | None | Mandatory, iterative, gated |
| Billing | Optional / internal | Shopify Billing API required for most charges |
| GDPR webhooks | Limited scope | Mandatory data-request/erasure handlers |
| Hardest part | Integrating with your systems | Coping with every store on the platform |
The cheapest mistake to avoid: paying for a public app when a custom one would do. If the goal is to fix your own store's problem, a custom app does it for a fraction of the cost and skips review entirely. Only pay for public when selling the app to other merchants is the actual point — and prove it on one store first.
The visible features are the commodity. Here is the invisible work that separates a company that has shipped real Shopify apps from one that has only built demos.
Once you know which app you're building, the next question is who builds it. Here's the honest trade-off.
| Option | Typical cost | Reliability | Best for | Main risk |
|---|---|---|---|---|
| Freelancer | ~$30–$120+/hr, wide spread | Varies wildly by who you get | A bounded custom app or a fix | Bus factor of one; nails the demo, not the review, billing, or edge cases |
| Generalist agency | $$–$$$ | Good code, shallow Shopify depth | Teams wanting process and a warranty | Learns Shopify's review and Billing API on your budget |
| Shopify specialist (e.g. Duskel) | Custom from ~$3k; public far higher | High — has shipped past review and billing | Public apps and anything touching billing or webhooks | Costs more per hour than a freelancer |
Rule of thumb: a contained custom app can go to a strong freelancer. Anything public — review, the Billing API, GDPR webhooks, multi-store robustness — is where a specialist earns its fee, because those are exactly the parts a generalist discovers, and re-bills you for, mid-project.
Pricing follows the same fork. A custom app is contained and cheap; a public app is a software business and priced like one. These are indicative 2026 ranges — the full cost breakdown lives here.
| App type | Complexity | Rough cost | Timeline |
|---|---|---|---|
| Custom / private | Simple connector | from ~$3k | 2–4 weeks |
| Custom / private | Medium (own back end, sync) | ~$8k–$20k | 4–10 weeks |
| Public App Store | Simple / narrow | ~$20k–$40k | 2–4 months |
| Public App Store | Medium (billing, onboarding, support) | ~$40k–$80k | 3–6 months |
| Public App Store | Complex (real-time, multi-store, high volume) | $80k–$150k+ | 6 months+ |
Skip the portfolio screenshots — anyone can show a clean admin UI. Watch for these instead.
Shopify apps are one of those things where the demo and the product are almost different disciplines. Anyone can wire the Admin API to a screen and make it work once. Making it pass review, bill reliably, stay in sync when webhooks misbehave, and keep a busy merchant's storefront fast is the actual job — and it's invisible until it's missing.
We build production software and run our own products, so we've met these failure modes ourselves rather than reading about them. We'll tell you straight when a custom app beats a public one, scope the review and Billing API work honestly instead of discovering it mid-project, and build webhook handling that survives a real store's traffic. No fabricated case studies — just the engineering judgement that keeps a Shopify app from becoming a support ticket. If you want a straight quote, private or public, tell us what you're building and we'll scope it.
The invisible platform work: passing App Store review, billing through Shopify's Billing API, processing webhooks that arrive out of order or twice, keeping the storefront fast via theme app extensions, and implementing the mandatory GDPR compliance webhooks. Those parts never show in a demo and are exactly where cheap apps fail, so they're what separates a company that ships a durable app from one that hands you a working prototype.
For a contained custom app on your own store, a strong freelancer is fine and cost-effective. For anything public — App Store review, the Billing API, GDPR webhooks, and robustness across stores you'll never see — a Shopify specialist earns its fee, because those are precisely the parts a generalist or lone freelancer discovers, and re-bills you for, partway through the project.
A custom (private) app is built for one store against data and a theme you control, skips App Store review, and can bill however you like. A public app is a product that installs on any store, must pass Shopify's review, must bill through the Billing API, and must implement GDPR compliance webhooks. It's not a bigger custom app — it's a software business with a Shopify-shaped front door, and it's priced accordingly.
A focused custom app starts around $3k and ships in a few weeks. A public App Store product with its own back end, the Billing API, onboarding, and review typically runs $20k to $80k, and a complex real-time multi-store app can pass $150k. The range is wide but honest — it depends almost entirely on how much back end sits behind the app.
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