Shopify theme developer and custom app integration: where to hire

Your Shopify theme has a bug that costs you orders, and someone on your team still copies orders into the warehouse system by hand. You know you need help. The open question is where to find it. This article shows where to find a Shopify theme developer and custom app integration help, and how to check each candidate before they touch your store.

The short answer: you are hiring for two jobs. Theme repair happens in Liquid, Shopify's template language. Integration happens through the Admin API, the door Shopify gives other systems to read and write store data. A few people do both well, and many do one.

You will leave with a one-hour diagnosis, a way to choose between fix and rebuild, a comparison of hiring channels and a paid test you can run this week. None of it needs you to write code.

Two jobs: theme repair and integration#

Most briefs arrive as a single sentence: fix our Shopify and connect it to our system. Inside it sit two jobs with different skills, different risks and different ways of checking the result. Splitting them lets you compare quotes fairly and hire the right person for each.

Theme repair in Liquid#

Theme work covers the broken cart drawer, the slow collection page and the variant picker that shows the wrong price. A good Shopify Liquid developer knows the Liquid reference the way an accountant knows tax code. They also know which parts of a theme are safe to edit and which will break at the next update.

If you want to see what a theme developer actually touches, how the Liquid theme system is built walks through sections, snippets and templates.

Integration work through the Admin API#

Integration work keeps data in step between Shopify and another system. It runs on the Admin GraphQL API and on webhooks, which are messages Shopify sends when something happens, such as a new order. The result you want: nobody retypes orders, stock counts match, and a failed sync is noticed in minutes.

When the other system is a CRM, how to hire a Shopify CRM integration team goes deeper on that case.

When one team can do both#

One team can do both when it has a Liquid specialist and an API developer working from the same brief. That helps most when the two jobs touch each other, for example a theme that shows live stock from your inventory system. Ask who writes the theme code and who writes the integration code, and who answers when the two disagree.

Diagnose your theme before you hire#

An hour of diagnosis gives every candidate the same facts and gives you a way to read their quotes. You can do most of it from the Shopify admin and a speed report.

App bloat and leftover code#

Open your installed apps and write down each one with the problem it solves. Many apps add scripts to every page. Some leave snippets in the theme code after you uninstall them, which keeps loading files for a tool you no longer use.

Ask each candidate to list which apps could be removed and which leftover code they find. The cost side of installed apps is worth a read before that call. Often the cheapest fix is a cleanup, not new work.

Speed and Core Web Vitals#

Run your home page, a collection page and a product page through PageSpeed Insights, and note the Core Web Vitals. Google's documented targets for a good experience are 2.5 seconds for LCP (how fast the main content appears), 200 milliseconds for INP (how fast the page answers a tap) and 0.1 for CLS (how much the layout jumps), measured at the 75th percentile of visits.

Save the numbers. They become the before picture, and the developer's work is judged against them.

Theme version and update status#

Check which theme you run and its version in the Online Store section of the admin. Then ask whether the code was edited directly or customised through sections and settings. The Shopify theme documentation explains the modern structure.

A theme several versions behind with edited core files costs more to update than one kept close to its original. Tell candidates which case you have.

Fix the theme or rebuild it#

A targeted fix is the right call more often than people expect, and a rebuild is sometimes cheaper over time. Your diagnosis tells you which.

When a targeted fix pays off#

A fix pays off when the problems are few and the theme is sound underneath. The signs:

• One or two named bugs, such as the cart drawer or a checkout redirect.
• A theme on a recent version with small edits.
• Speed problems that trace to a handful of apps or large images.
• A design your team still likes.

When a rebuild is cheaper over time#

A rebuild pays off when every fix costs more than the last. The signs are core files edited by several people, sections hard-coded in templates, no working way to take theme updates, and a design that no longer matches your brand. Paying twelve small invoices to patch the same theme can add up to more than one clean build.

Illustrative price ranges for each path#

The table below shows illustrative ranges for four situations. Each row is an example, such as a store with 12 installed apps and a theme two major versions behind. Real quotes depend on your diagnosis and your market.

A quote that is far below the others usually covers less. A quote far above often prices a rebuild you did not ask for. Ask both to explain the difference in plain words.

Shopify custom app integration: three routes#

There are three ways to connect Shopify to another system, and the right one depends on who owns the workflow. You do not need to learn the technology. You need to know what each route gives you and what it asks of you later.

Custom app for one store's workflow#

A custom app is built for your store only and is not listed publicly. It calls the Admin API with the permissions you grant, listens to webhooks and carries your exact rules, such as sending wholesale orders to your ERP with your own tax codes. You own the logic and can change it as the business changes. This suits a workflow that is specific to you and that you expect to keep for years. The integration service page shows how werun.dev scopes this kind of work.

Public app when a listing already exists#

If your ERP, shipping carrier or CRM already has a Shopify app, start there. You install it in minutes and the vendor maintains it. The trade-offs are a monthly fee and the limits of what the app exposes. When your process fits the app, this is the cheapest and fastest route.

Middleware such as n8n for quick links#

Middleware tools such as n8n connect Shopify events to other tools with visual workflows. They are fast to build and good for simple links: a new order posts to a team channel, a paid order creates a row in a sheet. Upkeep sits with whoever owns the workflow, and long chains of steps can get hard to follow. For a deeper look, see n8n vs Zapier vs Make.

What a good integration does on failure#

Every integration works on a good day. The one worth paying for also handles the bad day: your ERP is down for ten minutes, an order arrives twice, a product code does not match. A well-built integration queues the order, retries, logs each attempt and tells a person when it gives up.

Order sync path

1. 01Order createdShopify sends a webhook
2. 02App queues orderChecked and held safely
3. 03ERP callApp sends the order onward

• ADone and loggedCall succeeds, result recorded
• BRetry and alertBack to the queue until it succeeds
  1. Log each attemptEvery try is recorded
  2. Alert a personIf retries run out

Flow showing an order moving from Shopify through a webhook and queue to the ERP, with failed calls retried and logged

Ask candidates to describe this path before they describe anything else. Their answer tells you whether they have run integrations in production.

Where to hire: directory, marketplace or agency#

You can find help in three places, and each one moves effort to a different person. The question is who does the vetting, who is accountable when something breaks and who stays after launch.

What each channel does well#

The Shopify Partner Directory lists agencies and freelancers with profiles, services and reviews, which makes it a good place to build a shortlist. Freelance marketplaces such as Upwork give the widest range of prices and the fastest start, and you do the vetting yourself. An agency costs more per hour and gives you one accountable party that can cover both jobs.

If the question is who stays after the fix, freelancer vs agency for website maintenance compares the two on safety and continuity.

Questions to ask in the first call#

A first call of twenty minutes tells you a lot. Ask:

1. Which stores like mine have you fixed, and can I see the result?
2. Will you work on a duplicate theme and show me a preview before anything goes live?
3. Who writes the theme code and who writes the integration code?
4. What happens when the integration fails at night?
5. Who owns the code and the credentials when the work ends?
6. Who do I call in month three?

Protect the store: access, backups and staging#

The safe setup lets a developer work for days without any shopper noticing. It rests on three habits: access you can revoke, a copy of the theme to work on and a way back.

Give access that can be revoked#

Use a collaborator account or a staff account with only the permissions the job needs, and remove it when the work ends. Never share your owner login. If a candidate asks for it, treat that as a signal to pause.

For integrations, API credentials belong to your Shopify account. Keep them in a place you control, and rotate them when the developer leaves.

Work on a duplicate theme, never the live one#

A duplicate theme is a full copy that only your team and the developer can preview. Changes there reach no shopper until you publish. This is the single most useful habit for keeping the store up.

1. Add a collaborator account

   Grant only the permissions the job needs and set a date to remove it.

2. Duplicate the live theme

   Rename the copy with the date and the purpose, so everyone knows what it is.

3. Work on the copy

   The developer edits only the duplicate and keeps a short change log.

4. Preview and test on a real phone

   Check the cart, checkout path and the pages that earn the most.

5. Publish and keep the old theme

   The previous theme stays in the library as your rollback for a few weeks.

Ownership belongs in the same conversation. Agree in writing that theme code, custom app code and credentials are yours, and that the developer hands over a repository or an export at the end.

Vet a Shopify developer: test and red flags#

A small paid test shows more than a portfolio. You pay for a few hours, on a duplicate theme or a test connection, and you see how the person works.

A paid test task for each job#

For a Liquid developer, pick one real bug from your diagnosis and one leftover app snippet. Ask them to fix both on a duplicate theme, explain each change in plain words and show a before and after speed report. You are judging clarity as much as code.

For an integration developer, ask for a read-only connection first. A short query like this should return your five latest paid orders from a development or test store:

{
  orders(first: 5, query: "financial_status:paid") {
    edges {
      node {
        id
        name
        displayFulfillmentStatus
      }
    }
  }
}

Then ask what they would do if the receiving system rejected one of those orders. The answer should include retries, a log and an alert.

• Works on a duplicate theme or test store, never the live one
• Explains each change in plain words
• Names which apps can be removed and why
• Uses webhooks with retries for integrations
• Stores secrets outside the theme files
• Documents the work in a short written note
• Hands over the code and the credentials at the end

Red flags during the quote#

Some signals show up before any work starts. Watch for:

• A fixed price with no diagnosis and no written scope.
• A request for your owner login.
• A plan to edit the live theme directly.
• API keys pasted into theme files, where any visitor could find them.
• No answer to what happens when a sync fails.
• Refusal to hand over the code at the end.

One flag is a question to ask. Three are a reason to keep looking.

Where to start this week#

Write a one-page brief. On the top half, list the theme symptoms with the page, the device and the speed numbers. On the bottom half, state the integration goal in one sentence, for example: paid orders reach our ERP within five minutes, and failures alert the operations team.

Send that page to three candidates from the channel that suits you, ask for a written scope, and run the paid test with the strongest two. If you want one team to handle the theme, the integration and the maintenance after, tell us your goal. werun.dev works on Shopify stores, replies in under 2 hours on business days and stays after the launch, so nothing falls between two vendors.

Frequently asked questions#