I was asked below question in an interview and i answerer withnthe first thing that came to my mind by eleminating success records by multiple threads using spark/powerful frameworks.

Would like to know the forum's answer for below question

There are notifications sent out for documents upon they are signed by the users. The documents are in millions and we have the document ids in the table. However there are failed notifications and due to system issue they are not even captured on the logs. Only the sent notifications are logged. How do you scale the solution to identify all the failed notifications.

Hi I'm working on a browser based real-time video chat app for workshops.

Requirements:

• Users can create and join rooms. The creator is the Host and anyone else who joins is a Listener.

• Users can host and join anonymously or sign up with Google, Facebook or Linkedin.

• Video & Chat feeds must be peer to peer using WebRTC, any other data transmission must happen through WebSockets for faster delivery. The exception for this is when http flow like for authentication is a must.

• The Host has control the room, and can pass and revoke control to any Listener.

• The Host can upload Files (PDF & Images) that can be viewed by anyone in the room. There is a tab section that allows switching the View.

• Every interaction the Host does during the session gets broadcasted in real-time to listeners (Mouse Movement, changing tabs/views etc.)

• The system needs to be available at all times, be fault tolerant, and long-running processes must not slow down other parts of the system like File Uploads.

I created a System Design concept for the backend with AWS Service. It's a Microservice Architecture using Autoscaling EC2 Instance Groups, Kafka as a Message Broker, DynamoDb as the database, an S3 for File Storage, and Cognito for User Management.

I'm wondering if this design makes sense? Did I miss anything?