Background

The company has a REST API to allow users to create accounts, add cities they're interested in, and view the current weather data in those cities. It's a very popular API used by millions of people each day, and has a diverse user base. This API is written in Python's Flask framework, and uses PostgreSQL as it's data storage layer. It's not perfect though, and there are a number of enhancements and bug fixes that need to be made to it. This is where you come in.

Interview Goals:

• Ability to pick up a codebase, understand the basics, and provide value quickly
• Knowledge of advanced data management concepts (caching, data tiering (in-db, file storage))
• Knowledge of MVC paradigm

Prerequisites

• Create a Docker Hub account at https://hub.docker.com/signup
• Download Docker Desktop
• Run Docker Desktop locally to start up Docker to allow you to run this application
• Have a way to make API calls. We recommend Postman.

Start Application

• Run docker-compose up --build (This will take some time to build everything up the first time you run it)

Stop Application

• CTRL+C from the application
• Run docker-compose down

View Database

In your favorite Postgres database viewer, you can connect to it to see the tables via:

Host: localhost
Port: 5432
Database: postgres
Username: Postgres

This database does not have password authentication enabled.

Sample API Calls

Create User

POST localhost:80/users

Request Data:

{
    "name": "test"
}

Response Data

{
    "name": "test"
}

Get User

GET localhost:80/users/test

Response Data:

{
    "name": "test",
    "cities": [
        {
            "name": "chicago",
            "temp": 43.9,
            "pressure": 1021,
            "humidity": 100
        }
    ]
}

Add User to City

POST localhost:80/users/test/cities

Request Data:

{
    "name": "detroit"
}

Response Data

{
    "name": "test",
    "cities": [
        {
            "name": "chicago",
            "temp": 43.9,
            "pressure": 1021,
            "humidity": 100
        },
        {
            "name": "detroit",
            "temp": 48.29,
            "pressure": 1025,
            "humidity": 87
        }
    ]
}

Requirements

1. Implement the create user endpoint. Deal with the problem if the user already exists, and return the serialized response that uses the to_json method
2. Change the city temperature to display as a user-readable format (ex. 46.5F instead of just 46.5)
3. The weather API is $1/API Call. Explain (don't code) why this is a problem and various options to solve it