Building a Custom Ecommerce Cart for a Top-Notch Shopping Experience


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Cart abandonment is a rampant problem throughout the ecommerce industry — the rate hovers at around 79% across all industries, according to Salecyle — and it’s costing companies dearly. 

The ecommerce shopping cart serves as a virtual container where customers can accumulate goods for purchase before proceeding to checkout. 

The shopping cart serves multiple purposes, including: decision making, managing quantities, and inventory management.

A quality ecommerce cart features an intuitive interface.  It should clearly display the selected items, quantities, prices, and the option to remove or adjust items. The shopping cart icon should also be prominent and accessible from any webpage so customers can complete their purchases at any point.

The power of custom shopping carts

Developing a custom shopping cart can involve a significant time and cost investment, including with design, development, debugging, and testing. Still, it can benefit businesses seeking greater customization and flexibility than an out-of-the-box solution can provide. 

While ecommerce platforms provide pre-built carts with customization options, building one from scratch provides greater control over its core functionalities. For example, you can build a cart that implements personalized product recommendations at checkout and reflects the store’s branding. 

Custom shopping carts should be built with scalability in mind — features such as load balancing and database optimizations enable them to handle increased traffic. Remember the need for ongoing maintenance: identifying and fixing bugs and security vulnerabilities.

Shopping cart solutions are a crucial component of conversion optimization for online businesses.

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Key features of custom ecommerce carts

Ecommerce carts should integrate seamlessly within the website design for an online storefront. Security, ease of use, and scalability are absolute must-haves for earning customer trust and allowing the ecommerce solution to grow with the business.

User-friendly design.

Shopping carts should be easy to find and navigate. Here are some design tips to bear in mind:

  • Intuitive layout: Each item in the cart should include a thumbnail image, product name, price, and any selected variations (such as size or color) for easy identification.

  • Visual feedback: When customers interact with the cart, a brief animation or notification confirms the action was registered. 

  • Editable product details: Customers should be able to edit product details, such as size or color variations, without revisiting the product page. 

  • Persistent cart: The cart should retain items even if the customer leaves the website and returns later so they don’t lose their selections. 

  • Multiple payment options: Customers can pay with a debit or credit card or through a payment provider. 

Advanced security.

Shopping carts require advanced security measures to protect sensitive customer data, including credit card information and shipping addresses. 

  • Secure Socket Layer (SSL) encryption: Encrypt data transferred between the customer’s browser and the webserver to protect sensitive information entered during checkout. 

  • Payment Card Industry Data Security Standard (PCI DSS) compliance:  PCI DSS standards set guidelines for securely handling, storing, and transmitting cardholder data to prevent data breaches. 

  • Secure payment gateways: Choose a reputable payment provider such as PayPal or Stripe that handles transactions securely. Look for tokenization features, which replace sensitive payment data with unique tokens and prevent the customer from having to repeatedly enter this data.

  • User account security: Implement robust password policies encouraging users to create complex passwords. Allow users to set up security questions or account recovery options.

Integration capabilities.

Shopping carts are not standalone tools. They must seamlessly connect with third-party software. For example, integration with shipping providers enables automatic shipping rate calculations, label printing, and order tracking. 

Using APIs, online stores can offer multiple payment methods for enhanced convenience.

The shopping cart must also integrate with the online store’s inventory management system to update product quantities each time a purchase is completed. CRM integrations retain a customer’s complete purchase history, which is useful for marketing personalization and customer support. 

Finally, integration with your marketing automation platforms automates email campaigns, cart abandonment recovery, and customer segmentation.

Personalized recommendations.

Shopping carts provide an unparalleled opportunity for cross-selling and up-selling when the customer intends to purchase. 

Product recommendation algorithms can suggest items similar to or better than items currently in the cart. Some options include: frequently bought together, recently viewed, or similar products.


As an ecommerce website grows, its shopping cart functionality must accommodate increased traffic and transaction volume. Scalability enables this software to handle more demand without compromising performance.

Sales promotions, holidays, or viral marketing can lead to sudden spikes in website traffic. A scalable shopping cart ensures fast-loading webpages and a smooth checkout process regardless of demand spikes.

Multi-currency and language flexibility.

Supporting multiple currencies and languages is a crucial feature for an ecommerce shopping cart, especially if you're targeting a global audience. This enables small businesses to provide a localized and user-friendly experience. 

Let customers select their preferred language or be redirected to a custom webpage for their region. Prices should be displayed in the local currency, plus applicable overseas shipping fees, tariffs, and taxes. 

General custom shopping cart costs

Building a custom shopping cart involves stages, from initial development to ongoing maintenance. Costs also depend on whether you have an in-house dev team or hire an agency or freelancer. 

Initial development.

Development costs vary widely depending on complexity, design requirements, and integrations. Here’s an overview of the costs involved in the shopping cart development phase:

  • Planning and requirements gathering: Define the shopping cart’s features, functionalities, and user experience. It also includes creating wireframes, templates, and mockups to visualize the cart's layout and design.

  • Design and user interface development: This phase includes creating the visual shopping cart design, considering factors like branding, user experience, and responsive design across devices.

  • Back-end development: The most lengthy — and expensive — part of the process involves implementing back-end functionality, including product catalog management, inventory tracking, user accounts, cart management, payment processing, order processing, and database setup.

  • Front-end development:The second most expensive phase is creating the user interface, integrating design elements, and ensuring responsive and user-friendly interactions.

Testing and quality assurance.

Before a custom shopping cart goes live, it must be declared bug-free, secure, and fully functional. This process entails the following:

  • User authentication: Implementing user registration, login, password management, and security measures like encryption and data protection.

  • Testing: Rigorous testing to identify and resolve bugs, ensure functionality, and validate security measures.

  • Launch and deployment: Preparing the shopping cart for deployment on a server, configuring domain and hosting settings, and ensuring a smooth rollout.

Ongoing maintenance.

Shopping carts may encounter bugs that disrupt the customer experience (eg: discount codes don’t work or a payment gateway malfunctions). Here’s an overview of maintenance costs:

  • Bug fixes and security patches: Monitoring bugs and glitches that arise over time and shipping software updates to address newly discovered security weaknesses. 

  • Performance optimization: Testing and optimizing shopping cart performance to ensure fast loading times, smooth navigation, and efficient server utilization.

  • Database management: Regular maintenance to optimize queries, manage data integrity, and prevent performance issues.

  • Server maintenance and hosting costs: Ensuring server infrastructure is maintained and optimized for performance and security.

Maintaining a custom ecommerce cart

Ecommerce carts can require periodic troubleshooting, security patches, and more.  

Regular security audits.

Security audits uncover vulnerabilities in the shopping cart system that could lead to data breaches, compromising customer trust, and exposing sensitive information. 

These vulnerabilities include outdated software, improper configurations, coding errors, or overlooked security measures. Updates, patches, and security fixes help safeguard the system.

Monitoring user behavior.

Ecommerce shopping carts are a treasure trove of customer behavioral data, helping startups and enterprise-level stores preemptively address customer pain points. 

For example, pinpointing where customers drop off in the conversion funnel to investigate the root causes of cart abandonment. Or, if customers routinely purchase certain items together, you can offer them as a bundle to incentivize larger purchases.

User behavior data allows ecommerce sites to segment customers based on shopping habits and create targeted marketing campaigns. 

Recent trends like persistent shopping carts, guest checkout options, and chatbot integrations have enabled businesses to enhance the shopping cart experience. An inferior checkout page leads to lost sales. 

Stay informed on the latest trends in ecommerce shopping cart functionality by reading ecommerce trade publications, attending conferences, and monitoring competitor strategies. 

Ensuring seamless integrations.

Integrations are crucial to shopping cart functionality. Cart integrations automate order fulfillment and customer relationship management, saving time and reducing manual tasks. Integration with inventory systems ensures that product availability is current, reducing the risk of overselling or disappointing customers.

Specific integrations provide real-time updates, allowing customers to see accurate product availability, shipping estimates, and order status. 

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The final word

Custom shopping carts represent a significant investment, but given their importance in optimizing conversion rates, they should not be skimped on. Building a custom cart from scratch with personalized recommendations, custom pricing, and advanced security controls can help customers feel secure in their purchases. 

It also provides the business with valuable upsell and cross-sell opportunities. BigCommerce’s Cart API lets you integrate any custom shopping cart with your online storefront.

When deciding between a custom shopping cart versus a pre-built solution, such as a plug-in, open-source software, or shopping cart software, consider business needs, budget, time to market, and the availability of web development talent. 

FAQs about custom ecommerce carts

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