1. How to Approach a Design Question
1
The picture to keep in your head2
1.1 What is a system design interview, and what isn't it?3
1.2 What is the interviewer actually scoring?4
1.3 What's the step-by-step framework?5
1.4 How do you manage a 45-minute round?6
1.5 What questions should you ask first?7
1.6 What's the difference between functional and non-functional requirements?8
1.7 What's an API, and why define it before drawing boxes?9
1.8 How do you sketch the data model?10
1.9 What does a good high-level design look like?11
1.10 How do you choose what to deep dive into?12
1.11 How do you talk about trade-offs?13
1.12 What if you get stuck or don't know something?14
1.13 What are the most common mistakes?15
1.14 What does the bar look like: fresher vs SDE-2?16
Memory card and where the analogy breaks17
Practice: five levels18
Interview questions19
Solutions20
Sources21
Code lab1. How to Approach a Design Question
1.14 What does the bar look like: fresher vs SDE-2?
3 min read+10 XP
At the architect's desk: A junior architect is expected to draw a house that stands up and has every room. A senior one is expected to know what happens in an earthquake, a flood, or when the family doubles in size.
In the interview: The same question is asked at different levels, and the bar moves.
| Fresher / new grad | SDE-2 (around 2 to 4 years) | |
|---|---|---|
| Requirements | Asks the basic SCALE questions | Spots the non-obvious ones (abuse, hot keys, compliance) |
| Design | A working high-level design with the right building blocks | A design that also survives failures and growth |
| Deep dive | Explains one component clearly | Handles numbers, failure cases and alternatives in depth |
| Trade-offs | Names them when asked | Raises them unprompted |
| Driving | Follows the interviewer's lead | Drives the conversation, checks in, manages time |
Many companies don't run full design rounds for freshers at all, and when they do, they mostly look at clear thinking and the basics. Expectations rise sharply from SDE-2 upwards. The levels and titles vary by company, so treat this as a rough guide.
Memory code: "Fresher: it works. SDE-2: it survives."