Hire a Shopify Developer: Project, Monthly Retainer or Review?

Once you know you need a Shopify developer, the next question is how to engage them. Most work fits one of three shapes: a project with a fixed scope, ongoing development paid by the month, or a short technical review before anything bigger. Picking the wrong shape is a common reason custom work runs over budget or stalls after launch.

This guide explains when each one fits, how to scope it, and what to agree before work starts. If you are still deciding who to hire, read how to hire a Shopify app developer first. If you are not sure custom work is the answer at all, start with when to build a custom Shopify app.

The three shapes at a glance

	Fixed-scope project	Monthly retainer	Technical review
Fits best	One app, integration or migration with a clear result	An app or integration you already run and keep changing	A planned build, or an app someone else built
You pay for	An agreed result	A share of a developer’s time each month	A short, bounded piece of analysis
Main risk	Scope changes halfway	Paying for time that is not used well	Treating the review as the fix
Agree first	What “done” means, and how changes are handled	Priorities, response times, what counts as urgent	What the review covers and what you receive

A fixed-scope project

A project suits work with a clear end: a custom app that does one job, a connection between Shopify and your ERP, or a migration with a deadline, such as moving Shopify Scripts to Functions or REST to GraphQL.

It works when you can describe the result before the build starts. “Hide express delivery for orders over 20 kg to the Canary Islands” is a project. “Make our checkout better” is not yet.

To scope it well:

• Write the rules down. One sentence per rule, plus a few real examples, including the awkward ones: a split shipment, a refunded line, a customer with two addresses.
• Name the plan. Some options depend on it. Custom apps that contain Shopify Function APIs, for example, only run on Shopify Plus stores. See what Shopify Functions can customise.
• Say what “done” means. Which cases must work, on which stores, and who tests them.
• Agree how changes are handled. New requests during a project are normal. Decide up front whether they wait for a second phase or change the estimate.

The brief template covers what to send so a developer can estimate the work properly.

A monthly retainer

A retainer suits software you already run and will keep changing: an app your team uses daily, an integration that grows with each new supplier, or several small tools that each need attention now and then.

Even a finished app needs upkeep. Shopify releases a new API version every three months and supports each stable version for at least 12 months, according to its versioning documentation. Webhooks fail, credentials expire, and platform changes such as market-driven shipping can change what an older app sees. A retainer gives that work an owner.

To make a retainer work:

• Keep one list of priorities. One person on your side decides what comes next. Otherwise the developer chooses, and the urgent pushes out the important.
• Agree what urgent means. For example, orders not syncing or checkout blocked. Agree how quickly those get a response, and through which channel.
• Ask for a short monthly note. What was done, what is planned, and anything at risk, such as an API version nearing the end of its support window.
• Review the size every few months. If the time is never used, make it smaller. If the list keeps growing, a fixed-scope project for the large item may be cheaper.

Our guide to maintaining a custom Shopify app lists what the routine work covers.

A technical review

A review is a short, bounded piece of analysis that ends in a written answer, not in code. It fits two situations.

Before a build. You have a plan, and you want to know whether it is possible on your plan, what it will touch and where the risks are, before paying for the build. A good review often finds a simpler route: a public app, a Flow workflow, or a smaller custom app than you expected. See Shopify Flow vs a custom app.

Before switching developers. Someone else built the app, and you need to know what you have: where it runs, which accounts own it, which API version it calls, and what is likely to break. Our checklist for taking over a Shopify app from another developer covers what a review should look at.

Ask what you will receive at the end. A useful review gives you a list of what works, what is at risk and what to do first, in plain language you can share with whoever builds next.

Mixing the shapes

The shapes combine well. A common path is a review, then a project for the main build, then a small retainer to keep it running. Starting with a review also lets you judge a developer on a small piece of work before you commit to a large one.

What to agree in every shape

Whatever you choose, put these in writing before work starts:

• Code and accounts. Who owns the code, and which accounts the app, its credentials and its hosting are created under.
• Store access. Give a developer a collaborator account with only the sections they need, never your own login.
• Data. What the app stores, where, and how it is deleted after uninstall.
• Testing. Changes are tested on a development store before they reach your live store.
• Handover. Documentation on what the app does, where it runs and how to deploy and turn it off.

For a closer look at pricing, see what drives the cost of a custom Shopify app.

FAQ

Is it cheaper to hire a Shopify developer by the project or by the month?

For one job with a clear result, a project usually costs less, because you pay for the result. For software you keep changing, a retainer is usually cheaper than a series of small projects, each with its own scoping.

How much upkeep does a custom Shopify app need?

It depends on the app, but every app needs some. Shopify releases a new API version every quarter, and webhooks, credentials and hosting need watching. Plan for upkeep from the start.

What should a technical review of a Shopify app include?

Where the app runs, which accounts own the app and its credentials, the API version it calls, its webhooks, what data it stores, and a short list of risks and next steps.

Can I start with a small piece of work first?

Yes, and it is a good idea. A review or the smallest useful version of the app shows you how a developer communicates, tests and hands over before you commit to more.

Talk to us

The team behind StoreFleet: Inventory Sync is a dedicated team of Shopify app developers, building for e-commerce since 2021, and works in all three shapes. We build and run more than ten Shopify apps of our own, and our page on hiring Shopify app developers explains what we take on. Send a short brief and we will reply with how we would approach it.