Pivot order-status counts
Company: Instacart
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: Medium
Interview Round: Onsite
##### Question
Given an orders table (order_id, shopper_id, order_date, status, …), pivot the data so that each row is one shopper and each column shows the count of orders for a specific status (e.g., DELIVERED, CANCELED, RETURNED). Provide an efficient Java solution that works on a platform without external date-parsing libraries.
Quick Answer: This question evaluates data transformation and aggregation skills, specifically pivoting relational order data into per-shopper status counts, along with efficient Java implementation and handling of date-parsing constraints without external libraries.