How do you assess the complexity level of a given task?

The assessment of the complexity level of a task usually includes several aspects:

• Work volume: how much code or components need to be written.
• Unknown factors: whether there are new technologies to work with.
• Timeframes: how urgent the task is to be completed.
• Impact on the system: how much the task affects critical parts of the application.
• Dependencies: whether integration with other modules or services is required.

Practically, I break down the task into subtasks, estimate each by time and complexity, consider risks and experience with similar tasks. If in doubt, I clarify requirements with the customer or colleagues.