Adding a new feature to your eCommerce site sounds simple.
But deciding how to implement it? That’s where things get messy fast.

Do you:

• Build something custom from scratch?
• Install a third-party app and hope it covers your needs?
• Use what’s already built into your platform?

If you’ve ever wrestled with these questions (or paid for something only to find out it already existed), this guide is for you.

We’ll break down a step-by-step process to help you scope smarter, avoid unnecessary development work, and make tech decisions that align with ROI—not just ambition.

Step 1: Define the Real Problem to Solve

Before you touch code, install anything, or start searching for apps, zoom out and ask: What’s the actual problem we’re solving?

Let’s take a "Back in Stock" notification as a real-world example. At first glance, it sounds like a UI issue—just add a button that says “Notify Me.” But if you look closer, it’s a visibility and communication problem. A product comes back in stock, but no one knows. Meanwhile, interested customers who’ve been waiting are left in the dark.

That’s missed revenue, plain and simple.

Now flip the script. If that same product sold 25 more units at $150 with a 10% margin, you’d generate $375 in profit—from one item. Multiply that across your catalog and the opportunity becomes substantial.

This is where strategy starts: with a clear goal. Improve revenue and customer satisfaction by making restocks visible. When your team and stakeholders are aligned on the real problem, the entire implementation process gets smarter and more focused.

Step 2: Get Specific on Requirements (Before You Build)

This step is often where the wheels come off. Teams get excited, start building, and only later realize they missed something crucial—or overengineered something that didn’t matter.

Before you dive into implementation, get clarity on what the feature really needs to do. Not in vague terms like "just work" or "match our competitors." We're talking functional, user-facing requirements.

Let’s go back to the "Back in Stock" example. At its core, you likely need to show a "Notify Me When Back in Stock" button on sold-out products. That’s your baseline. You’ll also want a simple way to collect email addresses—ideally in a mobile-friendly form—and send a notification email when that product is restocked.

But beyond that core, you need to decide what’s mission-critical versus what’s a nice-to-have. Can logged-in users opt in automatically, without retyping their email? Do you need this to sync with your email platform like Klaviyo or Mailchimp? Should your team have access to an admin dashboard to view and manage signups? What about customizing the email that gets sent—do you need branding controls, or is a plain notification enough?

These questions are critical. Some features are essential to solving the user’s problem. Others can be rolled out later once the core functionality is proven. The danger lies in building everything at once without a clear prioritization. That’s how projects balloon in scope and timelines slip.

Start lean. Validate quickly. And focus first on the pieces that move the needle.

Step 3: Evaluate What Already Exists

Here’s where things get interesting. Most merchants assume their only choices are custom or bust. But the truth is, many platforms already offer core functionality—or the ecosystem around them does.

So before you build anything from scratch, ask: is this already included in our platform?

Platforms like Shopify, BigCommerce, and Magento have more built-in functionality than most people realize. And even if it’s not available out of the box, there may be a free or low-cost plugin or app that handles it.

Start by doing a quick audit:

• Search the app store or extension marketplace for your platform.
• Ask ChatGPT: “Does [platform] offer built-in [feature] functionality?”
• Look at what other merchants in your industry are using.

If you find something promising, don’t just install it blindly. Run a Lighthouse audit to establish your performance baseline, install the app, and then test again. Does it slow your site down? Does it integrate smoothly with your stack? How’s the mobile experience?

Even if the app doesn’t do everything you dreamed of, it might get you 80% of the way there—and serve as a valuable proof of concept before you invest in a fully custom solution.

Step 4: Decide—Is It Worth Building Custom?

Let’s say you’ve done your homework. The feature isn’t built into your platform. The apps you tested weren’t good enough. And you’ve clearly outlined your must-haves.

Now, and only now, should you consider building custom.

But even then—it doesn’t have to be all-or-nothing. One smart move is to test with an imperfect or temporary solution first. Can your team live with something that’s not ideal for a month while you gather data and feedback? If so, you may find your custom scope shrinking—or evolving in smarter ways.

The best custom builds start when:

• You’ve validated the demand
• You’ve scoped the work based on real-world needs
• You’ve confirmed there’s no easier path

If you haven’t done that, you’re not ready to build. Yet.

How do I disable something without it affecting my store?

Not sure if something's being used? Try turning off one module at a time and testing the related functionality. Even eliminating just two unused modules is progress worth celebrating.

Final Thoughts: Build Smarter, Not More

Every week, we work with merchants who are trying to do the right thing—but end up building too fast, too custom, too soon. And we get it. When there’s pressure to deliver, it feels like forward motion is always the answer.

But sometimes the best decision you can make is to slow down and ask better questions.

Do we really need this? Is there a better way? What are we actually solving?

When you answer those honestly, you’ll make smarter decisions, avoid costly rework, and stay focused on what truly drives growth.

And if you want help sorting through your next feature decision, we’re here.
Whether it’s custom or plug-and-play, we’ll help you find the path that makes the most sense—for your site, your stack, and your goals.

Prefer to take this in video form instead?

I walk through this exact framework—complete with real examples—in Episode 22 of The eComm Buzz. You can watch it below.