Custom Web Application

Hundred Life Design:
QuickBooks Invoicing/Billing Integration


When your online business is unique, off-the-shelf eCommerce solutions won’t always cut it. Haystack client Hundred Life Design has created a custom web platform that connects experienced life coaches with clients from across the globe. Hundred Life Design came to Haystack as they looked to expand their offerings. With corporate partnerships and agent commissions on their roadmap, they realized they needed a way to automate their billing and invoicing process. They also realized it would require a partner with the ability to understand their singular business and the technical skill to create a custom ecommerce solution to meet their complex billing needs.

Project Solution

In close collaboration with Hundred Life Design, Haystack architected a solution that automates the generation of invoices and bills across a variety of scenarios involving discounted sessions, corporate partnerships and sessions that earn commission. A custom-built WordPress plugin handles the invoicing and billing logic and calculations. It then generates the appropriate bills, invoices and receipts via the QuickBooks Online API. This plugin integrates directly into the existing payment process on Hundred Life Design’s highly-custom WordPress website.

To ensure accuracy, the logic and calculations are wrapped in automated tests (think of it as someone double-checking your Excel calculations, but they’re a computer) and uses a popular open-source money calculation library to avoid rounding errors common in many applications. Connecting with third-party APIs like QuickBooks is a quick way to add powerful functionality to an app, but each connection requires that service to be available. Knowing that it’s better to plan ahead for issues, the logic, calculations and QuickBooks connections are wrapped in an error-monitoring service called AirBrake. Error monitoring helps ensure Haystack is the first to know should an API change or a third-party system go down.

The Haystack team is excited to see Hundred Life Design continue to grow and is honored to help make that growth possible.

project rundown


    Hundred Life Design (Phoenix, AZ)

  • DATE:

    October, 2020


    WordPress Plugin Development
    QuickBooks Online API Integration
    Veem Integration


Haystack is a certified Minority-Owned Business (MBE) that provides reliable software solutions for websites and web-based or mobile applications. Our US-based team’s expertise and customer service is unparalleled, serving small businesses, nonprofits, and enterprise clients across the country. Contact Us

The Heartland (IND)

735 Shelby St
Suite 35
Indianapolis, IN 46203

+1 480 331 1060

The Valley (PHX)

2801 E Camelback Rd
Suite 200
Phoenix, AZ 85016

+1 480 331 1060