Requirements

Functional Requirements:

1. Users should be able to view the songs list based on category.
2. Users should be able to view the songs based on their past history.
3. Users should be able to share the song link.
4. Users should be able to search for song, artists song etc.
5. Users should be able to play / pause/next/seek/shuffle/repeat songs.
6. System should be able to create/manage the playlist.
7. Users should be able to see recommended songs based on their past history.
8. Offline playback

Non-Functional Requirements:

Scale -> 500M

10M concurrent streams

100M+songs

Search latency < 200ms

Highly available system

Song start time ~200ms

Support audio for lower network bandwidth as well

Capacity Estimation

100M songs 5 min avg len and 128KbPS

500M * 16KB * 60 ~ 8000GB * 60 ~480TB for one bit rate

Other bit rate will also be there

API Design

/search?search_term

GET /songs/recommendation

GET /songs

POST /playlist , body {name}

GET /playlist

PATCH /playlist/{name}, body {list of songs}

-> play any songs

GET /song/{songId}?quality={bitrate} -> Signed CDN urls, song MD

GET /song/{songId}/link

High-Level Design

Describe the overall system architecture. Identify the main components needed to solve the problem end-to-end. Use the diagramming tool to create a block diagram.

Database Design

Define the data model. Identify the main entities, their attributes, and relationships. Consider the choice of database type (SQL vs NoSQL) and justify your decision based on access patterns...

Detailed Component Design

Deep dive into 2-3 key components. Explain how they work, how they scale, discuss tradeoffs, capacity, and any relevant algorithms or data structures.