Case study · CatchBack Cards
How CatchBack Cards catches cross-device UI bugs before their users do
Got fed up with many UI bugs occurring across different device types and screen sizes. We used Lucent to figure out what was breaking, and it saved us a lot of time. Checking the most important parts of user logs is a really smart and useful concept.
Co-founder & CEO @ CatchBack CardsQ&A
- What does CatchBack Cards do?
- CatchBack Cards (YC W26) is a mobile app and web platform for Pokemon and sports card collectors. Users build custom mystery packs with cryptographically verifiable odds, rip open digital packs and get physical cards shipped, take instant buyback offers paid to Venmo or PayPal, and trade in a $1 marketplace.
- Why did CatchBack choose Lucent?
- CatchBack's users come in on every device imaginable — new iPhones, old Androids, tablets in landscape, browsers zoomed to 150%. Session replays were piling up in PostHog with no realistic way to watch them all. Error tracking caught crashes but missed the subtler UX failures that don't throw exceptions.
- What kinds of bugs has Lucent caught?
- Lucent flagged a pack-opening modal that was screaming "Error Loading Pack Opening" at users in bright red — even when the pull had succeeded and the card was safely in their vault. It had hit 198 sessions before anyone on the team knew. Separately, Lucent surfaced an SMS verification code failure blocking signups, caught at five sessions before it could become a pattern.
- How does Lucent fit into CatchBack's workflow?
- Lucent watches every PostHog session replay in the background and posts real issues straight to Slack with full reproduction context and a one-click path into Linear.
[ THE CHALLENGE ]
Catching the bugs that error trackers can't see
How CatchBack uses Lucent to find the silent UX failures that hurt the most
For CatchBack, the interface is the product. The thrill of the rip, the moment a pack reveals what's inside, the tap-to-accept on a buyback offer — every one of those happens in the UI, and every one of them has to feel right on whatever device a collector happens to be on.
The clearest case: when a user successfully pulled a card, a secondary animation occasionally failed to load. The pull worked. The card was in their vault. But CatchBack was showing a bright red "Error Loading Pack Opening" alert on what should have been one of the most rewarding moments in the product. Lucent surfaced this across 198 sessions before the team knew it was happening. "Static error tracking would have missed this entirely — nothing technically broke," says Joseph. The team reworked the modal to degrade gracefully and the error screen is gone.
A second example, caught early: users hitting a "Failed to send verification code" error during SMS phone verification. Five sessions over four days, all blocked at the top of the funnel. Lucent flagged it as high severity, surfaced it in Slack, and the team shipped a fix before it became a pattern.
Published