Design Video streaming application —

An interview assignment for technical skill assessment

Problem statement

An OTT platform WEBFLIX, a video streaming company need backend
application to maintain their streaming contents with following functionalities:
1. Insert/Add the video details
2. Retrieve the video details as per genre
3. Retrieve the video details based upon videoID
4. Retrieve the video details whose durations are more than 10 min

Create a high-level design document consisting of the below:
1. Architectural assessment: High level solution design including API documentation.
2. Coding Assessment: Create RestFul micro service + Skeleton UI as per the above given
scenario.

Approach

Functional requirements

• Users can publish/upload videos
• Users can search/watch videos based on genre, videoID and durations

Non-functional requirements

• highly available
• scalable
• good performance/response time should be less than a second.

Assumptions & Estimate

High level Design

HLD — video streaming app

Data Model

Data model

API Design

video upload API — large video file will be uploaded in chunks to the backend.

paths:
  /video:
    post:
      tags:
        - video
      summary: Add a new video to the store
      description: Add a new video to the store
      operationId: addVideo
      requestBody:
        description: Create a new video in the store
        content:
          multipart/form-data:
            schema:
              $ref: '#/components/schemas/Video'
              type: object
              properties:
                title:
                  type: string
                description:
                  type: string
                duration:
                  type: string
                genre:
                  type: string
                file:
                  type: string
                  format: binary
        required: true
      responses:
        '200':
          description: Successful operation
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Video'          
            application/xml:
              schema:
                $ref: '#/components/schemas/Video'
        '400':
          description: Invalid input
        '422':
          description: Validation exception
      security:
        - webflixstore_auth:
            - write:videos
            - read:videos

video get/search API — uses custom query language/grammar (ANTLR or JMESPath) to specify filter condition in the request.

paths:
  /video:
    get:
      tags:
        - video
      summary: Search and filter video by query
      parameters:
        - name: sort_by
          in: query
          description: sort result set by given list of video parameters
          example: duration,title
          required: false
          schema:
            type: string
        - name: page_size
          in: query
          description: fetch result sets limited by the given page size
          required: false
          default: 20
          schema:
            type: integer
            example: 25
        - name: page_no
          in: query
          description: fetch result sets for the given page
          required: false
          default: 0
          schema:
            type: integer
            example: 1
        - name: filter
          in: query
          description: filters search results by the given condition. uses custom query language/grammar (ANTLR or JMESPath) to specify filter condition.
          required: false
          schema:
            type: string
            example: ("duration">"00:20:00") AND ("genre"="fantasy")
      responses:
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Video'          
            application/xml:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Video'

        '400':
          description: Invalid ID supplied
        '404':
          description: Video not found
      security:
        - api_key: []
        - webflixstore_auth:
            - write:videos
            - read:video

Tech stack

frontend — reactjs, react-router

backend — nodejs as the application does mostly asynchronous IO ops

database — postgresql for meta data storage

video store — aws s3 for video files