A map for an open problem
System design questions are open ended, which can cause freezing or rambling. A structured framework gives a repeatable sequence to follow, so you always know the next step and the interviewer can follow your reasoning.
A common sequence
- Clarify requirements and scope.
- Estimate capacity and traffic.
- Define the API and data model.
- Draw the high level architecture.
- Deep dive into the hardest part.
- Discuss tradeoffs, failures, and scale.
Why structure helps
- It prevents freezing by always offering a next move.
- It signals seniority through a deliberate process.
- It paces the session so you cover breadth and depth.
- It is easy to follow for the interviewer scoring you.
Hold it loosely
The framework is a guide, not a rigid script. Interviewers may jump ahead or dwell on one area, and you should follow their lead while keeping the overall arc in mind. The goal is a coherent journey from vague prompt to defensible design, not ticking boxes in order.
Key idea
Use a repeatable sequence from clarify to wrap up so you never freeze on a blank canvas, while holding the steps loosely enough to follow the interviewer.