Design a Collaborative Todo List Service
Design a service that enables users to create and manage shared todo lists.
Core Functionality
The service must support the following operations on todo items within a list:
- Adding new items
- Editing existing items
- Assigning owners
- Setting due dates
- Reordering items
- Marking items as complete
Users should be able to see updates from other collaborators in near real-time.
Key Design Considerations
The design should explicitly address:
- Concurrent Editing: Handling multiple users simultaneously editing the same list.
- Authentication & Permissions: Implementing user authentication and per-list access control.
- Real-time Synchronization: Ensuring near real-time updates across web and mobile clients.
- Offline Support (if time permits): Mechanisms for handling offline or intermittent connectivity.
- Notifications: A system for delivering notifications related to assignments, comments, due dates, or completed tasks.
- Non-Functional Requirements: Trade-offs concerning reliability, observability, and data consistency.
Scale Assumptions
Assume a consumer or team-product scale, supporting:
- Millions of users
- Tens of thousands of concurrent collaborators
AI interview prep
Core dilemma
Balancing the need for near real-time, highly concurrent updates across multiple clients with strong data consistency and robust conflict resolution, all while operating at a large scale (millions of users, tens of thousands of concurrent collaborators).
3 tradeoffs and 3 stress tests locked
Interview prep
Unlock the interviewer X-Ray rubric, tradeoff matrix, stress tests, clarifying questions, and key concepts.
Design a Collaborative Todo List Service
Design a service that enables users to create and manage shared todo lists.
Core Functionality
The service must support the following operations on todo items within a list:
- Adding new items
- Editing existing items
- Assigning owners
- Setting due dates
- Reordering items
- Marking items as complete
Users should be able to see updates from other collaborators in near real-time.
Key Design Considerations
The design should explicitly address:
- Concurrent Editing: Handling multiple users simultaneously editing the same list.
- Authentication & Permissions: Implementing user authentication and per-list access control.
- Real-time Synchronization: Ensuring near real-time updates across web and mobile clients.
- Offline Support (if time permits): Mechanisms for handling offline or intermittent connectivity.
- Notifications: A system for delivering notifications related to assignments, comments, due dates, or completed tasks.
- Non-Functional Requirements: Trade-offs concerning reliability, observability, and data consistency.
Scale Assumptions
Assume a consumer or team-product scale, supporting:
- Millions of users
- Tens of thousands of concurrent collaborators