Death to Complexity: Building Your Custom eCommerce Cart

    Shreya Reddy
Listen to this article

You’ve figured out exactly what you want to accomplish.

You know that an off-the-shelf software solution is just not good enough for your business.

It’s time for you to invest in a custom eCommerce Cart.

Shopping Cart

Tailor-made software is great, right? I mean yes, it comes with a hefty price tag and will take up a lot of time, but in the end, it’ll deliver. You’ll be handed a solution that perfectly fits the bill, your sales will start to soar, business will increase significantly and your revenue is going to multiply by leaps and bounds.

That’s how things would work in a perfect world. In the real world, however, you’ll have to put in a great deal of time, efforts and research.

Don’t get me wrong. I’m all for a custom-build if that’s what’s needed. I’ve recently written about how some businesses just cannot rely on off-the-shelf eCommerce carts. If you’re one of them and you’ve decided to invest in a tailor-made cart, you need to have a clear picture of exactly what your eCommerce cart needs to turn out to be like.

Customization gives you the power to substantially expand the functionality of your cart, and so you should. Your cart is capable of taking your online business to a whole new level.

Let’s find out how!

The Simple Bare Necessities

You’re right in presuming that the primary objective of an eCommerce cart is to facilitate the purchase of your product. But there’s so much more to it than what meets the eye. I’m going to quickly go ahead and list down the basic tasks your eCommerce cart needs to carry out for you.

Adding a product to the cart along with its attributes

Product with its Attributes

That’s the Shopping Cart 101. When products are set up on your website, each of them is assigned a set of attributes. The most basic example would be that of a garment. The ‘color’ and ‘size’ of the outfit are known as its attributes.

When a product is displayed in your eCommerce cart, you need to make sure the relevant information is also fetched. In some cases, products have a lot of data associated with the backend software that doesn’t need to be displayed to the user. So that’s one thing you need to keep in mind.



Wishlists allow your customers to store some items in their cart that they can choose to buy at another visit.

Now, I can’t stress enough on how important wishlists are. When your customers save a product in their wishlist, they’re already halfway into making a purchase. It clearly indicates their interest in the product and gives you immense opportunity to retain your audience.

From the user’s point-of-view, a wishlist saves them quite some amount of time and effort. They don’t have to search for a product that they like all over again, they have the products handy when they’re looking to purchase at a more convenient time and they’re prepared for an upcoming sale or offer. This makes for the user-friendliness of your site and significantly increases customer satisfaction and of course, the sales.

Think about it. You wouldn’t want to lose out on a sale because your prospect couldn’t find the product they were looking for, would you?

Tax and Shipping Calculations

Tax and Shipping Calculations

In addition to the cost of the actual products, your eCommerce cart needs to calculate the sales tax and shipping charges, manage the exemption certificates and carry out address verification. Generally, your customer enters the delivery address and based on the type of product and this address, the sales and shipping charges are calculated. Hence, the address verification.

In the U.S. alone, there are over 11,000 taxing jurisdictions. In Texas, the state tax rate is 6.25%, but tax charged by the various cities and counties in the state may add up to an additional 2%, making it a total of 8.25%. So, how do off-the-shelf eCommerce carts handle the complexity of the local tax rates and keep up with the continual tax changes that occur throughout the year? They generally use tax charts or tables.

The problem here is that these tables don’t consider the local tax rates. Consequently, at the end of each quarter, companies must account for the missed local revenues and remunerate each tax jurisdiction within each state in which they have sold their products.

Your custom cart solves this problem by taking into account all of the local tax rates and the international taxes applicable – EU VAT, US Sales tax, Canadian VAT, Australian GST, New Zealand GST, Indian GST etc.

Yes, it’s a tedious task, but you’ll come to find it’s definitely worth it, especially at the end of a quarter.

As far as the shipping is concerned, you may be working with multiple different carries – USPS, FedEx, UPS, and DHL – each of which has their own specific packaging guidelines and shipping rates which need to be considered.

Payment Processing

Payment Processing

Since we’re talking about custom software here, I’ll just go over its immediate advantages. Building a Payment Gateway from the ground up gives you complete control over your transactions, allows you to implement unique business-specific features and relieves you from paying the processing fee that comes with Integrating a Payment Gateway. Most payment gateways charge for the setup, a recurring monthly cost for support and transaction fees.

However, building a custom Payment Gateway from scratch is going to cost you exorbitant amounts of money. It’s great if you can afford it, but there’s a ton of other factors to consider. The most important being, the security. You need to carefully plan out everything from the ease of the checkout process to the financial regulations and PCI compliance. You’ll need a hosted payment page, a well-documented API, as well as the administration and merchant dashboards to add the Payment Gateway to your website.

If you think you need a workaround when it comes to accepting payments, a ready-made Payment Gateway like PayPal or Stripe will work out just fine. A Payment Gateway checks the validity of cards and encrypts all the sensitive information like the Credit Card Number, its expiration date and the CVV. The best part about them is that there’s great scope for customization and implementing industry-leading features like enabling Express Checkouts, Setting up Payouts, Integrating Adaptive Payments etc.

Guest Checkout and Merged Accounts

Guest Checkout

Can you put a number on all of your accounts online? Personal and work email accounts, bank accounts, social media accounts, your Netflix account, a cab booking app, a food delivery app, a restaurant finder, an Amazon account, and the list goes on.

Almost every app or website you visit asks you to either ‘sign up’ or ‘sign in’. Naturally, a user’s reluctance towards entering their details time and again on online websites has vastly increased. This is precisely why a lot of online stores enable Guest Checkouts.

Guest Checkout allows your customers to make a purchase from your store without logging in or saving any information such as their username, password, phone number, shipping or billing address etc. When a purchase is made, only the details that are absolutely necessary (such as the email ID, Shipping address etc.) are collected and are not stored for further reuse.

While this can prove to be extremely effective in increasing conversion rates, it takes away a momentous opportunity from you in terms of building meaningful relationships with your clients. Also, managing reorders, refunds, exchanges, and returns can be a real nuisance. And from your clients perspective, having an account saves him/her the efforts of entering their details for every purchase on your site.

So, the perfect middle ground here would be to merge a guest account with a verified user account. You can accomplish this on account of the email addresses provided by the buyers. When you detect purchases made by the same email address, you can verify the account and seamlessly merge all of the user data (orders, addresses, carts, and other information) together. It’s a win-win for you and your customers!

Order Fulfillment and Tracking

Order fulfillment is the entire process that begins with an order being placed and ends when it is delivered to your customer.

Here’s what happens when delivering physical goods:

Order Fulfilment

Order tracking allows your customers to stay on top of their order at any given point in time. Your customers are a curious bunch. And keeping them satisfied needs to be at the top of your priority list. Hence, your eCommerce cart needs to be up-to-date throughout the entire order fulfillment process.

The most basic information your eCommerce cart absolutely needs to provide is theestimated delivery date and the Status of the order. The status of a product could be as follows:

Order TrackingIf you really want your eStore to stand-out, you can go one step further and allow your customers to track exactly where the product is after it has been shipped. This can easily be done with an API or other integrations with the shipper’s back-end systems or by providing a link to the order tracking page of the carrier’s website in a confirmation email.

Real-Time Inventory Management

Inventory Management

It goes without saying that you need to have a robust Inventory Management Software as part of your backend arsenal. Most organizations periodically update their inventory at predetermined intervals.

Real-Time systems, on the other hand, record every transaction instantaneously. As soon as an item is purchased, the product is debited from the stock. Similarly, an item appears ‘in stock’ as soon as it is sourced and ready for shipment.

In addition to the accurate sync of stock levels with the front-end portal, real-time inventory management also extends to order tracking at all stages of its movement until it reaches the customer. It could be a great asset to your accounting and finance system and could help keep your warehouse organized.

You can leverage this to offer transparency into your accurate stock position and motivate reluctant buyers to make a purchase. For example, a message that says ‘only 2 items left in stock’ can be that extra nudge your customer needs.

Another great functionality you can implement is the ‘In Cart Item Sellout’. This would basically mean that you hold a particular product that an account holder has added to his/her shopping cart, for a set period of time. Once your stocks dwindle, and this user doesn’t seem to be making a purchase, you can choose to sell it out to another customer. You can also automate the reminders and warning messages before you sell out an item from the user’s cart.

Import and export tools


If not right away, you’d eventually want to sell your products from multiple online stores or from marketplaces like Amazon or eBay. One obvious thing to do in that case would be to synchronize your inventory across all these stores. In order to get this done, you’ll need to equip your backend with some import and export tools.

This list could just go on and on. Having said that, these were the most fundamental features your custom eCommerce cart should ideally have. Let’s move on to,

The Discounts, Coupons, and Offers!

There are numerous different ways to leverage discounts, offers and sales to get new customers on board and ensure customer loyalty. Your shopping cart plays a huge role in the execution of your marketing strategies. I’m just going to quickly touch upon a few examples:

Promo Codes

Promo Code

Promo Codes or Coupon Codes are computer generated alphanumeric strings that you can provide to your most loyal customers. You could also use them to lure new buyers.

There are a number of ways in which these promo codes could work. They can be used to provide a fixed amount of discount on individual products, free shipping, a percentage off the entire purchase, or any other kind of discount you want to offer.

And where does your cart really come in?

During the Checkout process. Your customers can enter their promo code and avail the discount on their purchase during checkout. Your cart needs to check the validity of the codes and then approve and execute its use accordingly. These conditional coupon codes have to be assigned, limited and curated based on your marketing strategy.

Store Credits

Store Credits

Store Credits are issued to customers when they return merchandise that can’t be exchanged or isn’t eligible for a refund.

The cost of that product is stored in the form of ‘credits’ in your shoppers’ account which can be used by them on their next purchase. So, your eCommerce cart needs to process these credits when your customer chooses to use them up.

While store credits don’t really count as an offer or a discount, its execution definitely makes for a great way to retain your existing customers.

Gift Vouchers

GIft Voucher

Gift vouchers essentially entitle the holder to receive products or services of a specified sum from you. As they’re personal proposals of your satisfied customers, the vouchers are extremely targeted and the receivers of the voucher are a highly motivated bunch.

Implementing Gift Vouchers in your eStore creates a great opportunity for you to reach out to prospects that you wouldn’t otherwise get to directly.

Flash Sales

Flash Sale

Flash sales are discounts that are offered for a short period of time. In addition to being a great stock clearance tactic, Flash Sales serve as a valuable marketing gambit that drives impulsive buying.

Once you determine the goal of your flash sale, the target audience, and the execution strategy, you need to market it using social media, emails or other promotional means.

Now that you’re creating a hype, you need to ensure you can service your customers without any glitches. This, of course, translates to getting your cart on board.

The Marketing Nuts and Bolts

What’s a custom eCommerce cart without some marketing apparatus, right? Here’s a list of some aces that you should definitely have up your sleeve:

In-Cart Product Recommendations


In-Cart product recommendations are already pretty popular with major eCommerce stores. If implemented right, cross-selling or upselling from your cart could be a great asset that helps increase the average order value.

Cart Abandonment Recovery

Email Marketing

That’s the age-old eCommerce issue that your cart needs to tackle. Every minor detail involved in the execution of your entire eCommerce cart plays an important role in reducing your cart abandonment rate.

Having said that, there could be a couple of primary reasons that may lead your prospects to abandon their shopping cart. It could be a long and confusing checkout process, an unexpected shipping cost or maybe you aren’t offering sufficient payment options.

Once you identify such pain points, you can automate your retention email marketing campaigns depending on their intent.

Reserved Cart Timer

Flash Sale

You can choose to display a timer which indicates how long you’re going to hold the product for the user.

In the event of a sale or the release of a new high-demand product, this timer could be a great way to encourage your customers to make the purchase soon. Furthermore, you don’t lose out on business from shoppers who are keen on making a purchase because the product is being held up for an unsure buyer, which makes it all the more essential to implement a feature like this.

In Cart Item Sellout

Sold Out

When products in your user’s shopping cart are sold out, a simple message informing them of this sellout isn’t sufficient. The fact that a product is in their cart indicates interest, making it extremely critical for you to retain that particular sale.

You can do so using a simple pop up that offers to notify the buyer once the product is back in stock again. You could also choose to automatically restock the users shopping cart.

Promotion Reminders in the Shopping Cart


Again a great tool that can be used during an on-going sale. The trick here lies in finding the perfect balance between promotional content that’s too pushy and subtle reminders that prompt your users towards making a new purchase.

Internationalizing Your CartInternationalization

Now, that’s a whole other ball game. Internationalizing your eCommerce Cart involves everything from localizing it to enabling country-specific pricing, taxes, and marketing campaigns.

If it’s the right time to take your business global, you’ll need to run campaigns that are tailored to a specific set of audience and your cart needs to be absolutely ready for it.

Summing Up

Building a custom eCommerce cart that’s effective can create synergies if implemented well, and mountains of additional work if not. The key lies in deep-diving into every little detail of your project before you set out to build a complex enterprise solution like this one.

Although we’ve touched upon about a majority of the necessary tasks your cart needs to perform, it’s also important to make sure you optimize the checkout process and ensure your site and shopping cart are mobile-friendly. At the end of the day, all of these features within your cart are only meaningful if they leave your customers with a positive perception of the company and being mobile-ready is something you cannot afford to overlook.

What’s your Game Plan? How do you plan on Supercharging your eCart? Let’s talk about what else we can do to get the most out of a custom build. Over to you!

Shreya Reddy

Shreya Reddy

Leave a Reply

Your email address will not be published. Required fields are marked *

Get The Latest Updates

Subscribe to our Newsletter

A key to unlock the world of open-source. We promise not to spam your inbox.

Suggested Reads

Join our 55,000+ Subscribers

    The Wisdm Digest delivers all the latest news, and resources from the world of open-source businesses to your inbox.

    Suggested Reads