Knowledge Base | Daily Notes

Pramp- System design

Aug 30, 20242 min read

9 Oct, 2023.

URL shortner:

functional_requirement

  • Shortening the longer URL in shorter one.
  • Redirect.
  • No of years, 10.

non_functional_requirement

  • x request per minutes, 5 request
  • Read vs write??
    • 80% read and 20% write.
  • 1 request per minute *

Use it to share thoughts and resources, such as:

  • Features scope
  • API design
  • Pseudo code for specific components
  • Data model/schema
  • Back-of-the-envelope calculations
  • Reference links
  • Link to whiteboard or diagram such as https://sketchboard.me/new

URL-Shortener

URL Shortening services (e.g. bit.ly or tinyurl) take a long URL string and create shorter URL versions that redirect to the long URL.

Design a URL Shortener service.

This editor is synced in real time with your peer.

Use it to share thoughts and resources, such as:

  • Features scope
  • API design
  • Pseudo code for specific components
  • Data model/schema
  • Back-of-the-envelope calculations
  • Reference links
  • Link to whiteboard or diagram such as https://sketchboard.me/new

Good luck!

Lets say 5 requests per minute NF 80% 20%

Candidate (me):

  • 1 write request per minute * 60 * 24 * 365 * 10 (10 year is target) - y req.
  • 26 English
  • log??

Interviewing candidate: Tiktok (Modita)

This editor is synced in real time with your peer.

Use it to share thoughts and resources, such as:

  • Features scope
  • API design
  • Pseudo code for specific components
  • Data model/schema
  • Back-of-the-envelope calculations
  • Reference links
  • Link to whiteboard or diagram such as https://sketchboard.me/new

Good luck!

Features

  1. Register opening account
  2. Log in
  3. Upload
  4. News Feed
  5. Like Video
  6. Comment on Video
  7. Bookmarks

Non Functional

  1. 1 million daily active user
  2. Uploading?? 20K users uploading ⇒ Read heavy
  3. Available
  4. Less latency

APIs

  1. RegisterUser POST API
  2. GetUserInfo GET API
  3. Upload Content
  4. AccessNews Feed

News Feed User -⇒ LB -⇒ NewsFeedService -⇒ DB (U1 ⇒ List Users) MySQL -⇒ Fecth data from CDN -⇒ Amazon S3 -⇒ Redis Cache

User User Name ID Location Followers -⇒

Sharding? what data ⇒ User -⇒ Ho MySQL Master Slave Slave

DB -⇒ Normalised Keys

Geo Routing -⇒ WebServer —⇒ CDN Load NewFeed_1 User
Load -⇒ Hashing User 1 -100 NewFeed1 100-200 NewsFeed2 Round Robin Fashion

Caching Caching the User info etc following field etc Redis cache to cache the TimeLine aswell

Fault Tolerance ⇒ heartbeat? pricing? partition t. →

Least Recently User Or FIFO Video Duplication ⇒ Server Processing -⇒ broken chunks -⇒ Generate a Hash video -⇒

Graph View

Backlinks