While preparing iDeal of Sweden for Black Friday, we encountered a problem with how WooCommerce handles discount coupons. Our solution managed to reduce resource usage by 85%, which meant that we could easily handle traffic spikes of up to 10 orders per second without any problems.
A (slightly modified) solution has now been approved for release in the next major version of WooCommerce, version 3.6.
We are of course very happy to have been able to contribute to our community while helping our customers solve their problems. This will of course be celebrated with pomp and circumstance!
In addition to this, a new feature we created for wp-cli was also approved. What a week!