System requirements

Functional:

Shared document editing (among multiple users)

Document storage and retrieval

Authentication

Sharing documents between users

Non-Functional:

solution for handling conflict resolution

consistency > availability (latency before editing a document is okay, latency once editing a document with conflict resolution is not okay)

authentication and authorization

Capacity estimation

Data Types:

1. We need blob storage for storing documents
2. Store user information and access to blob storage (ie sharing documents with another user)

Data Requests:

1. Reads for getting the access patterns (bulk not often called reads)
2. Fetching blob data
3. Lots of writes and updates to blob storage (the hardest part of the problem)

API design

Access patterns:

1. Given a specific user, we need all blobs that the user created or has access to
2. Given a specific document, get all users that have access to that document

Update a given blob storage item while making edits

Database design

Data Storage:

1. Blob storage for documents
2. SQL database for user/document access

User:

ID

email

login/pass etc

Document:

document ID

User created

date created

date edited

shared true/false

DocumentAccess:

document ID

userID

time given access

authorization type (view/edit/etc)

revoked?

High-level design

UI:

Choose document for edit

Document editor screen

Backend:

API when defining what document you're using

conflict resolution while editing a document

Request flows

After the user logs in they get a view of their available documents for editing from the API database. They can then select one of the documents for editing. Multiple clients can edit the same document at a time. When a change is made it calls the conflict resolution API which updates the blob storage.

Detailed component design

Dig deeper into 2-3 components and explain in detail how they work. For example, how well does each component scale? Any relevant algorithm or data structure you like to use for a component? Also you could draw a diagram using the diagramming tool to enhance your design...

Trade offs/Tech choices

Explain any trade offs you have made and why you made certain tech choices...

Failure scenarios/bottlenecks

Try to discuss as many failure scenarios/bottlenecks as possible.

Future improvements

What are some future improvements you would make? How would you mitigate the failure scenario(s) you described above?