Shopify App Development Company for Custom Apps

Build the Shopify app your store or app business actually needs. Bytecode designs, builds, hosts, and maintains private apps, public apps, checkout extensions, and API integrations.

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up Top Rated on Upwork 148+ projects delivered New York studio · 24h replies

What you get

Shopify app development, done properly

Custom Shopify app development is not always the right move. If an existing app solves the job without risky workarounds, we will say so. When you need brand-specific logic, a public app product, or deeper systems integration, Bytecode can build it cleanly.

We work from New York and serve clients across the US. Shopify app platform rules change, so app scope, API use, checkout extensions, and review requirements are checked against current Shopify docs as of 2026.

Private Shopify Apps

Custom apps for one brand, built around your catalog, operations, fulfillment, subscriptions, reporting, or internal workflows. You get focused functionality without forcing your team into generic app behavior.

Public Shopify Apps

App products for founders building a Shopify app business. We can handle the app architecture, embedded admin UI, billing flow, install flow, permissions, and review readiness.

Checkout Extensions

Checkout UI extensions and Shopify Functions for stores where the plan and use case support them. We confirm the current Shopify requirements before writing code.

Admin API and Webhooks

Integrations using Shopify Admin API, Storefront API, and webhooks. Common use cases include ERP, 3PL, inventory, CRM, Klaviyo, HubSpot, and custom reporting systems.

Embedded App Admin UI

Admin screens that feel natural inside Shopify and are clear for your team to use. We design for store operators, not just developers.

Hosting and Maintenance

We can host, monitor, update, and maintain your app after launch. That includes API version updates, bug fixes, security reviews, and small product improvements.

How it works

From first call to launch

Audit the Need

We first decide whether custom app development is justified or whether an existing Shopify app is the better choice.

Scope the App

We define users, permissions, data flows, Shopify APIs, webhooks, hosting needs, and review requirements.

Build and Test

We build the app, test core workflows, handle edge cases, and check Shopify platform rules against current docs.

Launch and Maintain

We support deployment, app review readiness when needed, monitoring, fixes, and ongoing updates.

Why Bytecode

Why teams pick us for Shopify app development

Build vs Buy Honesty

A custom app is not always the right answer. If a trusted existing app can do the job with less risk, we will recommend it.

Senior Technical Judgment

Bytecode is led by founder and lead developer Tapabrata Goswami, Top Rated on Upwork with 148+ projects delivered and 98% client satisfaction.

Shopify and DTC First

We focus on Shopify and DTC brands first, then custom software for growing US businesses. That helps us design apps around real store operations.

FAQ

Questions, answered

Do you build private Shopify apps for one store?

Yes. We build custom private apps for one brand when Shopify settings and existing apps are not enough. Common needs include inventory logic, ERP or 3PL connections, reporting, custom order workflows, and CRM data sync.

Do you build public Shopify apps?

Yes. We can help founders build a public Shopify app product from the first technical scope through review readiness. We handle embedded app UI, permissions, billing logic, install flows, hosting, and maintenance planning.

Can you build checkout UI extensions and Shopify Functions?

Yes, when the store plan and use case support the required checkout customization. Shopify’s checkout and app extension rules change, so we confirm requirements against current Shopify docs as of 2026. We will tell you early if a requested checkout change is not supported.

Can you connect Shopify to ERP, 3PL, inventory, or CRM systems?

Yes. We build integrations using Shopify APIs, webhooks, queues, and custom middleware when needed. We can connect Shopify with ERP, 3PL, inventory systems, CRMs, Klaviyo, HubSpot, and internal tools.

Will you get our public app approved by Shopify?

We prepare your app for review and build against Shopify’s published requirements. Shopify controls the review decision, so we do not guarantee approval. We can help respond to review feedback and make required changes.

Do you maintain apps after launch?

Yes. We can maintain hosting, API version updates, bug fixes, monitoring, and small feature changes. This is important because Shopify app platform rules and API versions change over time.

Guides from our blog

All articles

E-Commerce Oct 25, 2026 12 min read

Shopify Custom App Development: When Your Store Needs Its Own App

A practical guide for DTC brands deciding when to build a custom Shopify app instead of stacking more off-the-shelf apps.

Read article

E-Commerce Oct 25, 2026 12 min read

How to Hire a Shopify Developer in the USA: Freelancer, Agency or In-House

A practical hiring guide for DTC founders choosing between a Shopify freelancer, agency or in-house developer in the US.

Read article

E-Commerce Oct 31, 2026 11 min read

Shopify B2B Wholesale: Set It Up the Right Way

A practical guide to Shopify B2B wholesale setup: price lists, company accounts, payment terms, taxes, and when to use Shopify Plus vs. apps.

Read article

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Taking on new projects

Build the Right Shopify App

Send your app idea or integration problem, and Bytecode will reply within 24 hours with a practical next step.

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