System Design : Part 2

This is the second instalment of the System Design notes I'm creating. If you haven't read the first section yet, here's a link to it. This article will discuss data, data flow, and databases.

Data & Data Flow

Data is the core entity of any system. Data is represented differently at different layers.

• Bussiness Layer : Texts, Videos, Images, Lists
• Application Layer : Json , XML
• Data Stores : Tables, Indices, Lists, Trees
• Network Layer : Packets
• Hardware Layer : 0s & 1s

Once you get the clear understanding on how the data flows the journey of system design is halfway done.

Data Stores

• Databases [E.g. Username, User’s phone number, City, Address]
• Queues [E.g. Send sms request, Send email request]
• Caches [E.g. Request : Response]
• Indexes [E.g. Most searched item, Items searched in 1 hour]

Data Flow Methods

• APIs
• Messages
• Events

Data Generation

• Users interact with system and create more data.