Pair Programming Interview

A banking application used for Carta's pair programming interviews. Candidates work with an interviewer to extend and improve the app during the session.

Overview

The app lets users view bank accounts (checking, savings, credit), see transaction histories, and search transactions by merchant, category, or memo.

Tech stack: Django + Django Ninja API backend (SQLite), React + TypeScript + Vite frontend, styled with Tailwind CSS and shadcn/ui.

Data Models

• Account — belongs to a User. Has a name, type (checking/savings/credit), and optional notes. Balance is computed from transactions.
• Transaction — belongs to an Account. Tracks date, memo, amount, and type (debit/credit). Optionally linked to a Category and Merchant.
• Category — a unique name (e.g. "Groceries").
• Merchant — a unique name (e.g. "Whole Foods").

API Endpoints

Method	Path	Description
GET	/api/users	List all users
GET	/api/users/{id}/accounts	List accounts for a user (with computed balances)
GET	/api/accounts/{id}/transactions	List transactions for an account (supports ?search=)

Prerequisites

Please ensure prior to your interview that you are able to run the application via the instructions below.

• Docker

Running

docker compose up --build

Visit http://localhost:5173.