Aircall.io - Backend technical test

This test is a part of our hiring process at Aircall for backend positions. It should take you between 3 and 6 hours depending on your experience.

Feel free to apply! Drop us a line with your Linkedin/Github/Twitter/AnySocialProfileWhereYouAreActive at jobs@aircall.io

Summary

The purpose of the test is to reproduce one of our typical use case on the backend part of Aircall: call forwarding.

The story is the following:

Jane (CEO), Peter (CTO) and Luke (COO) are in the same company.
The company has 3 different phone numbers: Main Office, Sales number and Support number.
The company is using Aircall in order to manage its calls! Currently they are using two features of Aircall: call forwarding and call history.
Every user is connected to at least one Aircall App.

It's 9AM in the office and first calls are coming in!

Instructions

Code

In this repository you'll find a simple Rails project with some models:

User : the Aircall users. We won't use a Company model in this test, so User is the main object in the hierarchy.
CompanyNumber : it represents the lines of the company (the previous Main office, Support number and Sales number for example)
UserNumber : it represents the apps of each User (mobile, desktop...)

In order to make and route calls, you'll extend this Rails project by creating an interaction with Plivo's API. You'll only use SIP endpoints and we'll consider that the lines of the company (Main Office, Sales number, Support number) are SIP endpoints too. Callers will launch calls from SIP endpoints as well.

Please keep these points in mind:

The focus of this test should be the interaction between your Rails server and Plivo on incoming calls. Do not customize forms or views in order to modify models (except if it helps you to test) - it's a backend test.
Use a seeds.rb file in order to fill the database because we will launch the rake task db:seed.
You can add all the models you need.
Do not add tests in your submission, except if you have extra time.
You can add as many gems as you want or change the ruby version.
Prepare deployment of your project on a simple Heroku dyno (for example).
In order to test the interaction between Plivo and your local environment, you can use tunnels like ngrok.com.
If you're on Mac, use the free Telephone application in order to register to SIP endpoints. For other systems, there are a lot of free SIP client too.
You'll have three types of SIP endpoints: one for the caller, one for the company's line and one for the users' apps.
For the caller's SIP endpoint you can use the Direct Dial App on Plivo. This endpoint used is not part of your system and will only be used to call the company's number.
You don't need to handle outbound calls from users' apps, but only inbound calls. So you can use the Direct Dial App for these endpoints too.
Your system has to be extendable. It should work the same way if we add users, numbers or apps.

Use case

Each app of each user has registered to a different SIP endpoint and they will get calls through these SIP endpoints.

The use case we want to reproduce is the following:

A customer is calling one of the number of the company.
The call has to be redirected to the apps of the users.
If nobody took the call on a specific line, the caller will leave a voicemail.
The call has to be logged in the database (with a reference to the number, to the user who answered or an URL to the voicemail).

Submission

Fork this repository and send us a pull request. We'll review it and get back to you in order to talk about your code!

Main steps

[ ] Create a Plivo account and read the doc.

[ ] Create SIP endpoints on Plivo for the caller and the users' apps.

[ ] Create Application and SIP endpoints you'll use for company's numbers.

[ ] Create a Call model in order to store call history and voicemails.

[ ] Redirect incoming calls to users' apps by interacting with Plivo.

How to run this app?

1/ Update the application.yml file with your keys and env variables

PLIVO_AUTH_ID: "Your AUTH_ID"
PLIVO_AUTH_TOKEN: "Your AUTH_TOKEN"

HOST: "my-aircall.herokuapp.com"
PROTOCOL: "https"

DIRECT_DIAL_APP_ID: <APP_ID>

2/ Create, migrate and seed the DB

bundle exec rake db:create
bundle exec rake db:migrate
bundle exec rake db:seed

3/ Call one of the company number endpoint with the caller endpoint provided by the seed

4/ See the call history

Go to http://localhost:3000 (or https://my-aircall.herokuapp.com for the live demo)

tildedash / backend-test-2