● Free · no signup · ~5 min
Try a system design drill
One focused, interview-style prompt. Write a short answer and an AI interviewer grades it in seconds.
The prompt
Design the data model for an e-commerce cart + order history, where carts mutate often and orders are immutable once placed.
Cart abandonment analytics laterOrders must be auditable10M users
Your answerFill in each line — schema, bullets, or prose.
Store ◯·Schema / key fields ◯·Access patterns ◯
No diagram needed for a drill — that's what the full interview is for.