// Product design case study
Account Blocking: Cutting a fraudster's 30-minute window to seconds
A request to rebuild a cleanup tool became a fix for the problem it was cleaning up after.
Summary
Product Designer. I framed the problem and owned the epic.
- Context
- DAT runs a freight load board. When a customer account is compromised, fraudsters use it to post fake loads, and a compliance team works to shut them down. Blocking a user ran through a chat-bot command outside the customer service app, and clearing the fraudster's postings meant switching to a legacy tool.
- Problem
- The brief was feature parity: bring bulk delete of fraudulent postings into the customer service app. Watching the compliance team work showed the deletions were a symptom. A blocked fraudster kept access for up to 30 minutes and could keep posting the whole time, so rebuilding bulk delete would have meant rebuilding a tool that was already losing.
- Approach
- I started with the compliance team before the epic opened, through recorded workflow walkthroughs, check-ins and interviews, and wrote a Compliance Rep persona with jobs to be done. I shared a walkthrough recording with engineering and product leadership, and it became the rallying cry for the pivot from cleaning up fraud to stopping it. I designed blocking into the user's profile in the customer service app, with a required reason and a clear blocked state, inside the app's existing menu rather than a new big red button.
- Result
- v1 shipped in July 2026. Authorized reps block a user from their profile with a recorded reason, and a block now ends the user's existing sessions, designed to take effect in about 2–3 seconds. With no product manager in place, I led the effort to gather the v2 requirements in one shared place.
- What's next
- v2 brings bulk delete back, along with the investigation fields reps asked for and retiring the chat-bot commands. The team hasn't assessed the v2 requirements yet.
- How I worked
- I built a quick coded prototype in v0 so stakeholders and engineers could click through the flow in meetings rather than imagine it. Later, after testing the customer service app by hand, I used AI to help update the compliance rep's user journey.
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