Design Task Management System
Design a task management system where users can create, assign, update, and track tasks with statuses and priorities.
A task management system is a software tool that helps individuals and teams plan, organize, assign, and track tasks in an efficient and structured manner. It plays a key role in improving productivity, accountability, and collaboration especially in fast-paced, team-driven environments.
Popular tools like Trello, Asana, and ClickUp are examples of task management platforms designed to streamline workflows and improve team efficiency.
In this chapter, we will explore the low-level design of a task management system in detail.
Lets start by clarifying the requirements:
1. Clarifying Requirements
Before starting the design, it's important to ask thoughtful questions to uncover hidden assumptions, clarify ambiguities, and define the system's scope more precisely.
Here is an example of how a discussion between the candidate and the interviewer might unfold:
Candidate: Should the system support task hierarchies, such as subtasks under a parent task?
Interviewer: Yes, tasks can have one or more subtasks.
Candidate: What metadata should be associated with a task?
Interviewer: Each task should have a title, description, due date, priority, tags, and a status like “To Do,” “In Progress,” or “Done.”
Candidate: Should the system support grouping tasks under a task list or project?
Interviewer: Yes, tasks can be organized under a project or task list for better structure and management.
Candidate: Should users be able to perform a full-text search on task details?
Interviewer: Full-text search on task titles should be supported. In addition, filtering by status, assignee, priority and sorting by due date should also be supported.
Candidate: Should the system maintain an activity log for each task to track updates and progress over time?
Interviewer: Yes, we should log important events such as task creation,, status changes, and assignment modifications.
Candidate: Are there different user roles, and should permissions vary based on roles?
Interviewer: For now, we can keep it simple. Assume all users have the same level of access.
After gathering the details, we can summarize the key system requirements.
1.1 Functional Requirements
- Users can create, update, and delete tasks
- Each task should support metadata such as title, description, due date, priority, status, and tags
- Tasks can have subtasks, supporting a parent-child relationship
- Tasks can be grouped under task lists or projects (e.g., "Project Phoenix Bugs," "Q4 Marketing Plan").
- Users can assign tasks to themselves or others (single assignee per task)
- Users can update the status of a task (e.g., from 'To-Do' to 'In Progress').
- Users should be able to view tasks in a list sorted by due date or priority.
- Users can search tasks by title and filter tasks using keywords, status, user, etc.
- The system should maintain an activity log for each task to track creation, updates, and status changes
1.2 Non-Functional Requirements
- Consistency: Task updates (e.g., status changes, reassignments) should be reflected immediately and reliably across the system
- Scalability: The system should scale to support a large number of users, tasks, and projects
- Maintainability: The codebase should follow good object-oriented principles to ensure modularity, testability, and ease of future development
- Extensibility: The design should be flexible enough to accommodate future enhancements such as recurring tasks, notifications, file attachments, or role-based permissions