A problem shape is the structure underneath a customer problem, independent of the industry it arrives in. Our case library’s shapes include triage and prioritize (more work arrives than people can handle), unify fragmented sources (the same customer lives in several systems that disagree) and response and throughput (something takes too long, and nobody owns the whole wait). A child welfare hotline and a security team drowning in alerts share a shape: more incoming work than people, and a real cost to handling it in the wrong order. Problem shapes are our method for organizing practice; no employer publishes a list of them.
In FDE interviews
Decomposition prompts can arrive in industries you have never worked in, and our practice questions do too: a stadium’s ticket scanners that go offline, a subscription business losing customers after the first renewal. Recognizing the shape in the first minutes gives you your opening questions and the tripwires that shape tends to hide, so you spend the round on the customer’s specifics instead of rebuilding a method. A strong candidate says the shape in plain words and treats it as a guess: “Customers leaving after the first renewal is a detection problem: something is going wrong inside noisy usage data, and someone has to act before the renewal date. So my first questions are how you define a cancel as a query, how early you would need to know, and who would act on it. If it turns out you already know why they leave, this becomes a prioritization problem and I’ll change course.”
The lesson Problem shapes: recognizing a case you have already solved lays out each shape with its first questions and likely tripwires.