Design Google Docs.

Designing Google Docs involves a distributed system focused on real-time collaboration, scalability, and data integrity. Key components include:

1. Client-Side Application: Handles user interface, local document state, and real-time input.
2. Load Balancers: Distribute traffic to ensure high availability and responsiveness.
3. Web Servers: Process client requests and manage document sessions.
4. Collaboration Service: Manages concurrent edits using Operational Transformation (OT) or Conflict-free Replicated Data Types (CRDTs) to synchronize changes across all clients in real-time.
5. Document Storage: Persists document data, likely using a distributed NoSQL database for scalability and fault tolerance.
6. Real-time Communication: Utilizes WebSockets or similar technologies for low-latency bidirectional communication between clients and servers.
7. Authentication & Authorization: Secures documents and user access.
8. Background Workers: Handle tasks like indexing, search, and generating previews.