Case Study: ThredUP.com achieves faster bug fixes and higher engineer productivity with FullStory

How thredUP Increases Engineer Productivity through Session Capture and Error Tracking

thredUP, the world’s largest online thrift and consignment store, prides itself on a strong engineering culture led by VP Engineering Dan DeMeyere and a focus on real customer experience rather than just aggregate metrics. The team faced hard-to-reproduce issues—most notably an A/B test where users in the “no-discount” group were still applying promo codes—and struggled to understand what customers were actually doing on the site.

By combining Rollbar for exception alerts with FullStory’s session replay, thredUP engineers could watch affected sessions, discover the root cause (customers pasting a referral-based promo from an old upsell), and fix it quickly. The duo also accelerated product validation during a site overhaul and made bug diagnosis far faster and more reliable, increasing engineer productivity and improving the customer experience.

ThredUP.com

Dan DeMeyere

VP Engineering