Ghosts in the Ledger

A easy Data Modeling interview practice problem on DataDriven. Write and execute real data modeling code with instant grading.

Domain

Data Modeling

Difficulty

easy

Seniority

L4

Problem

We run a B2B SaaS platform that bills customers monthly. Each invoice pairs a header carrying the billing period and running status with a variable set of charges for subscription tiers, usage overages, and one-time fees, where every charge locks in the price that was in effect when the bill was issued. Finance needs to see what each customer still owes as invoices age past their due date.

Summary

Invoices go out, partial payments trickle in, and some customers are three months overdue.

Practice This Problem

Solve this Data Modeling problem with real code execution. DataDriven runs your solution and grades it automatically.