System design of WhatsApp
system design of WhatsApp for Android.?
1. User Interface:
The user interface of WhatsApp for Android is designed to be user-friendly and consistent with the Android platform. WhatsApp's UI uses Material Design, a design language developed by Google, which provides a clean, modern look and feel to the app. Material Design is known for its use of bold colors, typography, and minimalist design elements. The UI allows users to send and receive text messages, voice messages, photos, videos, and documents. The app also includes features such as group chats, voice and video calls, and status updates.
References:
- Google Material Design: https://material.io/design
- WhatsApp's user interface explained: https://www.androidauthority.com/whatsapp-interface-explained-735368/
2. Message Encryption and Security:
WhatsApp for Android uses end-to-end encryption to secure messages and calls between users. This means that only the sender and receiver can read or hear the message or call, and not even WhatsApp itself can access the content of the communication. The app uses the Signal Protocol, which is an open-source protocol for secure communication, to encrypt messages and calls. The app also includes security features such as two-factor authentication and fingerprint authentication to protect user accounts from unauthorized access.
References:
- WhatsApp's security features: https://www.whatsapp.com/security/
- Signal Protocol: https://signal.org/docs/
3. Message Routing and Delivery:
When a user sends a message or makes a call on WhatsApp for Android, the app must route the message or call to the correct recipient. The app uses a centralized message routing system, which sends messages and calls to WhatsApp servers for processing. The servers use a complex routing algorithm to determine the best way to deliver the message or call to the recipient. The routing algorithm takes into account factors such as network conditions, location, and the status of the recipient's device.
References:
- WhatsApp's message delivery explained: https://www.whatsapp.com/faq/en/general/21082168
- Technical details on WhatsApp's message routing: https://www.slideshare.net/azrasharif/whatsapp-system-architecture-90064912
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4. Message Storage and Retrieval:
WhatsApp for Android must store and retrieve messages and media efficiently. The app uses a distributed database system, which stores messages and media on multiple servers around the world. The app also includes a local database on the user's device, which caches recent messages and media for fast access. The app uses a combination of techniques, such as data compression and deduplication, to reduce the amount of data that needs to be stored and transmitted.
References:
- WhatsApp's approach to data storage: https://www.whatsapp.com/security/WhatsApp-Security-Whitepaper.pdf
- Technical details on WhatsApp's distributed database: https://engineering.fb.com/2015/09/01/android/scaling-whatsapp-with-mysql/
5. User Authentication and Authorization:
WhatsApp for Android must authenticate and authorize users before allowing them to access their accounts. The app uses a phone number as the primary identifier for users. When a user registers for WhatsApp, the app sends an SMS message to the user's phone number, containing a verification code. The user enters the code into the app to verify their phone number and create their account. The app also includes security features such as two-factor authentication and fingerprint authentication to protect user accounts from unauthorized access.
References:
- WhatsApp's approach to user authentication: https://www.whatsapp.com/security/WhatsApp-Security-Whitepaper.pdf
- How WhatsApp verifies your phone number: https://www.whatsapp.com/faq/en/general/28030010
6. Audio and Video Encoding and Decoding:
WhatsApp for Android must encode and decode audio and video data for sending and receiving voice and video calls. The app uses a variety of codecs (encoding and decoding algorithms) to efficiently compress and transmit audio and video data over the internet. For example, WhatsApp uses the Opus codec for voice calls, which provides high-quality audio at low bitrates. The app also uses the H.264 codec for video calls, which is a widely used video codec that provides high-quality video at low bitrates.
References:
7. Push Notifications:
WhatsApp for Android uses push notifications to alert users of new messages, calls, and other events. When a user receives a message or call, the app sends a push notification to the user's device, which displays a notification on the user's screen. The app uses Google's Firebase Cloud Messaging (FCM) service to send push notifications to Android devices. FCM provides a reliable and scalable way to deliver push notifications to millions of devices at once.
References: