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Bitespeed Backend Task: Identity

Reconciliation

Meet the brilliant yet eccentric Dr. Emmett Brown, better known as Doc. Hopelessly stuck in 2023, he is fixing his
time machine to go back to the future and save his friend. His favourite online store FluxKart.com sells all the
parts required to build this contraption. As crazy as he might get at times, Doc surely knows how to be careful. To
avoid drawing attention to his grandiose project, Doc is using different email addresses and phone numbers for
each purchase.

FluxKart.com is deadpan serious about their customer experience. There is nothing more important than
rewarding their loyal customers and giving a personalised experience. To do this, FluxKart decides to integrate
Bitespeed into their platform. Bitespeed collects contact details from shoppers for a personalised customer
experience.

However, given Doc's modus operandi, Bitespeed faces a unique challenge: linking different orders made with
different contact information to the same person.

Bitespeed Needs Your Help!

Bitespeed needs a way to identify and keep track of a customer's identity across multiple purchases.
We know that orders on FluxKart.com will always have either an email or phoneNumber in the checkout event.
Bitespeed keeps track of the collected contact information in a relational database table named Contact .

{
id Int
phoneNumber String?
email String?
linkedId Int? // the ID of another Contact linked to this one
linkPrecedence "secondary"|"primary" // "primary" if it's the first Contact in th
createdAt DateTime

Bitespeed Backend Task: Identity Reconciliation 1

 updatedAt DateTime
deletedAt DateTime?
}

One customer can have multiple Contact rows in the database against them. All of the rows are linked together
with the oldest one being treated as "primary” and the rest as “secondary” .

Contact rows are linked if they have either of email or phone as common.

For example:

If a customer placed an order with

& phoneNumber=123456
email=lorraine@hillvalley.edu

and later came back to place another order with

& phoneNumber=123456 ,
email=mcfly@hillvalley.edu

database will have the following rows:

{
id 1
phoneNumber "123456"
email "lorraine@hillvalley.edu"
linkedId null
linkPrecedence "primary"
createdAt 2023-04-01 00:00:00.374+00
updatedAt 2023-04-01 00:00:00.374+00
deletedAt null
},
{
id 23
phoneNumber "123456"
email "mcfly@hillvalley.edu"
linkedId 1
linkPrecedence "secondary"
createdAt 2023-04-20 05:30:00.11+00
updatedAt 2023-04-20 05:30:00.11+00
deletedAt null
}

Requirements

You are required to design a web service with an endpoint /identify that will receive HTTP POST requests with
JSON body of the following format:

{
"email"?: string,
"phoneNumber"?: number
}

The web service should return an HTTP 200 response with a JSON payload containing the consolidated contact.

Your response should be in this format:

Bitespeed Backend Task: Identity Reconciliation 2

 {
"contact":{
"primaryContatctId": number,
"emails": string[], // first element being email of primary contact
"phoneNumbers": string[], // first element being phoneNumber of primary conta
"secondaryContactIds": number[] // Array of all Contact IDs that are "seconda
}
}

Extending the previous example:

Request:

{
"email": "mcfly@hillvalley.edu",
"phoneNumber": "123456"
}

will give the following response

{
"contact":{
"primaryContatctId": 1,
"emails": ["lorraine@hillvalley.edu","mcfly@hillvalley.edu"]
"phoneNumbers": ["123456"]
"secondaryContactIds": [23]
}
}

In fact, all of the following requests will return the above response (use toggle to expand)

{
"email": null,
"phoneNumber":"123456"
}

{
"email": "lorraine@hillvalley.edu",
"phoneNumber": null
}

{
"email": "mcfly@hillvalley.edu",
"phoneNumber": null
}

But what happens if there are no existing contacts against an incoming request?
The service will simply create a new Contact row with linkPrecedence=”primary" treating it as a new customer and
return it with an empty array for secondaryContactIds

Bitespeed Backend Task: Identity Reconciliation 3

 When is a secondary contact created?
If an incoming request has either of phoneNumber or email common to an existing contact but contains new
information, the service will create a “secondary” Contact row.

Example:

Existing state of database:

{
id 1
phoneNumber "123456"
email "lorraine@hillvalley.edu"
linkedId null
linkPrecedence "primary"
createdAt 2023-04-01 00:00:00.374+00
updatedAt 2023-04-01 00:00:00.374+00
deletedAt null
}

Identify request:

{
"email":"mcfly@hillvalley.edu",
"phoneNumber":"123456"
}

New state of database:

{
id 1
phoneNumber "123456"
email "lorraine@hillvalley.edu"
linkedId null
linkPrecedence "primary"
createdAt 2023-04-01 00:00:00.374+00
updatedAt 2023-04-01 00:00:00.374+00
deletedAt null
},
{
id 23
phoneNumber "123456"
email "mcfly@hillvalley.edu"
linkedId 1
linkPrecedence "secondary"
createdAt 2023-04-20 05:30:00.11+00
updatedAt 2023-04-20 05:30:00.11+00
deletedAt null
},

Can primary contacts turn into secondary?

Yes. Let’s take an example
Existing state of database:

{
id 11
phoneNumber "919191"

Bitespeed Backend Task: Identity Reconciliation 4

 email "george@hillvalley.edu"
linkedId null
linkPrecedence "primary"
createdAt 2023-04-11 00:00:00.374+00
updatedAt 2023-04-11 00:00:00.374+00
deletedAt null
},
{
id 27
phoneNumber "717171"
email "biffsucks@hillvalley.edu"
linkedId null
linkPrecedence "primary"
createdAt 2023-04-21 05:30:00.11+00
updatedAt 2023-04-21 05:30:00.11+00
deletedAt null
}

Request:

{
"email":"george@hillvalley.edu",
"phoneNumber": "717171"
}

New state of database:

{
id 11
phoneNumber "919191"
email "george@hillvalley.edu"
linkedId null
linkPrecedence "primary"
createdAt 2023-04-11 00:00:00.374+00
updatedAt 2023-04-11 00:00:00.374+00
deletedAt null
},
{
id 27
phoneNumber "717171"
email "biffsucks@hillvalley.edu"
linkedId 11
linkPrecedence "secondary"
createdAt 2023-04-21 05:30:00.11+00
updatedAt 2023-04-28 06:40:00.23+00
deletedAt null
}

Response:

{
"contact":{
"primaryContatctId": 11,
"emails": ["george@hillvalley.edu","biffsucks@hillvalley.edu"]
"phoneNumbers": ["919191","717171"]
"secondaryContactIds": [27]
}
}

Bitespeed Backend Task: Identity Reconciliation 5

 What stack to use?
Database: Any SQL database can be used
Backend framework: NodeJs with typescript is preferred but any other framework can also be used.

How to submit this task?

1. Publish the code repository to Github

2. Keep making small commits with insightful messages.

3. Expose the /identify endpoint

4. Host your app online and share the endpoint in the readme file. (You can use free hosting services like
render.com)

5. Note: Use JSON Body and not form-data for request payloads.

6. Submit the task here.

BiteSpeed - Backend Task Submission

https://forms.gle/3j3KF6zJumemhMkQ9

More about Bitespeed:

Way Of Life At BiteSpeed - Our Values & Purpose

BiteSpeed's Mission & the Future of Commerce

Bitespeed Backend Task: Identity Reconciliation 6