How an Agency Saved a Client €50,000 by Catching a Checkout Bug Early

For Shopify agencies, every missed bug is a potential crisis — not just for the client’s bottom line, but for the agency’s reputation. This real-world-inspired case study shows how one agency turned a near-disaster into a retention success story using proactive QA and automation.

The scenario

An established Shopify Plus brand had recently launched a flash promotion. Everything seemed fine — until conversion rates suddenly dropped by 40%. The cause? A minor JavaScript conflict introduced during a last-minute theme update had broken the mobile checkout button for certain devices.

The agency managing the store caught the issue within 30 minutes of deployment — before the client even knew something was wrong.

The catch

The agency had implemented Shoptest just a week prior. One of their test flows ran every 15 minutes, validating the cart and checkout process across devices. When the test failed, Shoptest immediately triggered an alert to the agency’s QA channel in Slack.

By the time the client started their day, the bug had already been diagnosed, fixed, and verified.

The result

The agency's swift response didn’t just solve a problem — it delivered measurable business outcomes that resonated far beyond the technical fix. Here's what happened next:

• Revenue protected: Estimated €50,000+ saved in lost sales

• Reputation strengthened: The client praised the agency’s quick action and renewed their retainer

• Trust built: The client approved expansion of QA automation across all future projects

The lesson for other agencies

This wasn’t just about saving money — it was about preventing escalation and preserving client confidence. When agencies catch issues before the client or end-customer experiences them, they not only protect revenue but also elevate the perception of their service. They become proactive partners, not just vendors. This shift repositions QA from being a back-office technical cost to a strategic, high-impact differentiator that directly contributes to client retention and long-term value.

How Shoptest makes this possible

What allowed the agency to catch this costly bug so quickly? It wasn’t luck — it was the result of integrating Shoptest into their QA workflow. Here’s how the platform empowered their team to act fast, stay informed, and deliver real value:

• Run tests on key store flows automatically and frequently

• Catch bugs in real-time, not after customer complaints

• Get notified immediately via Slack, email, or dashboard

• Prove your agency’s value with transparent test logs and uptime history

Final thoughts

In high-velocity eCommerce environments, mistakes happen — but they don’t have to become disasters. Agencies that arm themselves with proactive QA tools like Shoptest are better equipped to deliver stability, trust, and long-term growth for their clients.

Want to deliver results like this for your clients? Try Shoptest for Agencies →