Objective The main objective of this project is to create an API to manage clients and the loan payments control system from a fin-tech.
Purpose The purpose of this challenge is to test your ability to implement a solution given an abstract problem. You may find a problem in the asked task that you need to explain the problem and propose a solution to fix it.
Problem A fin-tech needs to create and manage the clients and keep track of the amount of money loaned and the missed/made payments. It also needs a place to retrieve the volume of outstanding debt at some point in time.
Business Rules
- If a client contracted a loan in the past and paid all without missing any payment, you can decrease by 0.02% his tax rate;
- If a client contracted a loan in the past and paid all but missed until 3 monthly payments, you can increase by 0.04% his tax rate;
- If a client contracted a loan in the past and paid all but missed more than 3 monthly payments or didn’t pay all the loan, you need to deny the new one.
Limitations Loans are paid back in monthly instalments; Can’t pay above loan amount; Will not be able to receive a value above the total.
Summary Create a client in the system.
Restrictions
- All fields are required;
- Validate the e-mail;
- Validate the CPF, only numbers;
- Validate telephone, accept only 11 characters. i.e: (11976548761);
Payload
name: the client name.
surname: the client surname.
email: the client email.
telephone: the client telephone.
cpf: the client (individual registration) identification.
Example of sent data
{`
“name”: “Felicity”,
“surname”: “Jones”,
“email”: “felicity@gmail.com”,
“telephone”: “11984345678”,
“cpf”: “34598712387”
}
Reply
client_id: unique id of a client.
Example of received data
{
“client_id”: 1
}
Summary Create a loan application. Loans are automatically accepted.
Restrictions
- In creating the Loan you should consider the last loan to decide the rate used;
- In creating the Loan can only be released if it is current with the current or does not have any;
- In the consultation of the Loan the date is not before the date of the beginning of the loan;
- In the Loan query, a data can’t be used later.
Payload
client_id: the client’s identification that contracted a loan.
amount: loan amount in dollars.
term: number of months that will take until the loan gets paid-off.
rate: interest rate as decimal.
date: when the loan was requested (origination date as an ISO 8601 string).
Example of sent data
{
“client_id”: 1,
“amount”: 1000,
“term”: 12,
“rate”: 0.05,
“date”: “2019-05-09 03:18Z”
}
Reply
loan_id: unique id of the loan.
instalment: monthly loan payment.
Example of received data
{
“loan_id”: “000-0000-0000-0000”,
“instalment”: 85.60
}
Notes
Loan payment formula
r = rate / term
instalment = [r + r / ((1 + r) ^ term - 1)] x amount
Example
For repaying a loan of $1000 at 5% interest for 12 months, the equation would be:
instalment = [(0.05 / 12) + (0.05 / 12) / ((1 + (0.05 / 12)) ^ 12 - 1] x 1000
instalment = 85.60
Summary Create a record of a payment made or missed.
Restrictions
- It is not possible to pay a different amount from that established in the loan;
- When creating the Payment, the payment value must be validated with the made and missed strings;
- In the creation of the Payment the date sent must be validated with the date of the day;
- In the creation of the Payment the value amount must be in dollars;
- In the creation of the Payment must be validated only one per month.
Payload
payment: type of payment: made or missed.
date: payment date.
amount: amount of the payment made or missed in dollars.
Example of sent data (Payment made)
{
“payment”: “made”,
“date”: “2019-05-07 04:18Z”,
“amount”: 85.60
}
Example of sent data (Payment missed)
{
“payment”: “missed”,
“date”: “2019-05-07 04:18Z”,
“amount”: 85.60
}
Summary Get the volume of outstanding debt (i.e., debt yet to be paid) at some point in time.
Restrictions No restrictions so far
Payload
date: loan balance until this date.
Example of sent data
{
“date”: “2017-09-05 02:18Z”
}
Reply
balance: outstanding debt of loan.
Example
{
“balance”: 40
}