Questions and Answers API

Overview

This project is an API infrastructure service for the question and answers module of a retail e-commerce application.

Technologies

Node.js | Express.js | PostgreSQL | AWS EC2 | NGINX | K6 | Loader.io

Discription

• Designed the back-end system with a scalable RESTful API and database(PostgreSQL)
• Utilized an ETL process from 18M data sources into a PostgreSQL database.
• Re-built an existing API service with Node.js and Express.js
• Optimized the performance by refining queries and identifying bottlenecks with stress tests, locally K6 and cloud-based Loader.io.
• Deployed the server and databse on AWS EC2
• Horizontally scaled 3 intances and set up a load balancer with caching through Nginx
• Achieved latency of 84ms and a 0% error rate, throughput of over 1000rps.

Installation and Setup

1. Fork and clone the repo and navigate to the root directory
2. To install dependencies:

npm install

Contributor

• Jongmyung Jeong

End points

List Questions

GET /qa/questions

Retrieves a list of questions for a particular product. This list does not include any reported questions.

{
  "product_id": "5",
  "results": [{
        "question_id": 37,
        "question_body": "Why is this product cheaper here than other sites?",
        "question_date": "2018-10-18T00:00:00.000Z",
        "asker_name": "williamsmith",
        "question_helpfulness": 4,
        "reported": 0,
        "answers": {
          68: {
            "id": 68,
            "body": "We are selling it here without any markup from the middleman!",
            "date": "2018-08-18T00:00:00.000Z",
            "answerer_name": "Seller",
            "helpfulness": 4,
            "photos": []
            // ...
          }
        }
      },
      {
        "question_id": 38,
        "question_body": "How long does it last?",
        "question_date": "2019-06-28T00:00:00.000Z",
        "asker_name": "funnygirl",
        "question_helpfulness": 2,
        "reported": 0,
        "answers": {
          70: {
            "id": 70,
            "body": "Some of the seams started splitting the first time I wore it!",
            "date": "2019-11-28T00:00:00.000Z",
            "answerer_name": "sillyguy",
            "helpfulness": 6,
            "photos": [],
          },
          78: {
            "id": 78,
            "body": "9 lives",
            "date": "2019-11-12T00:00:00.000Z",
            "answerer_name": "iluvdogz",
            "helpfulness": 31,
            "photos": [],
          }
        }
      },
      // ...
  ]
}

List Answers

GET /qa/questions/:question_id/answers

Returns answers for a given question. This list does not include any reported answers.

{
  "question": "1",
  "page": 0,
  "count": 5,
  "results": [
    {
      "answer_id": 8,
      "body": "What a great question!",
      "date": "2018-01-04T00:00:00.000Z",
      "answerer_name": "metslover",
      "helpfulness": 8,
      "photos": [],
    },
    {
      "answer_id": 5,
      "body": "Something pretty durable but I can't be sure",
      "date": "2018-01-04T00:00:00.000Z",
      "answerer_name": "metslover",
      "helpfulness": 5,
      "photos": [{
          "id": 1,
          "url": "urlplaceholder/answer_5_photo_number_1.jpg"
        },
        {
          "id": 2,
          "url": "urlplaceholder/answer_5_photo_number_2.jpg"
        },
        // ...
      ]
    },
    // ...
  ]
}

Add a Question

POST /qa/questions

Adds a question for the given product

Add an Answer

POST /qa/questions/:question_id/answers

Adds an answer for the given question

Mark Question as Helpful

PUT /qa/questions/:question_id/helpful

Updates a question to show it was found helpful.

Report Question

PUT /qa/questions/:question_id/report

Updates a question to show it was reported. Note, this action does not delete the question, but the question will not be returned in the above GET request.

Mark Answer as Helpful

PUT /qa/answers/:answer_id/helpful

Updates an answer to show it was found helpful.

Report Answer

PUT /qa/answers/:answer_id/report

Updates an answer to show it has been reported. Note, this action does not delete the answer, but the answer will not be returned in the above GET request.