At Mollie I did research on A/B testing on the mollie.com marketing website. The result was an A/B testing system created in React and Nodejs which serves visitors a variant of an A/B test experiment. Integrated with Google Optimize to analyse the data after completion. The result added less than 3 ms to the loading time.
About Mollie
Mollie is a Dutch Payment Service Provider offering payment solutions across Europe. Mollie became a ‘Unicorn’ valued at over €5B in 2021.