Loan Laux from Trellis shares their experiences building custom checkouts on BigCommerce using the open-source library Checkout JS from BigCommerce.
• https://trellis.co/
• https://github.com/bigcommerce/checkout-js
• https://support.bigcommerce.com/s/article/Optimized-Single-Page-Checkout?language=en_US
• https://developer.bigcommerce.com/stencil-docs/customizing-checkout/installing-custom-checkouts