Scheduling cron jobs = send emails to everyone who has recieved friend requests yesterday.

• npm cron-node

• npm date-fns

• Schedule a job

• Find all the unique emailswho have got connection requests in previous day

• send emails

• Advance technique : Queing , batching , npm bee-queue

WebSockets

• Build the UI for chat window - /chat/:targetUserId

• setup socket.io in backend

• npm i socket.io

• configuration on back-end

• client side configuartion

• Whenever there is a socket connection, we need to create a room. I has a room _id and can have multiple participants in the room.

• Steps involed during web socket connection:

  BackEnd and FrontEnd

  • initialize the socket
  • Establish connection - BE
  • join the room - FE
  • create secretRoom and let users join the room - BE
  • send the message - FE , BE
  • Disconnect the connection

  save messages to database

  • can be the first message
  • append to the existing messages

Payment Gateway Integration - RazorPay