90% fail system design interview within 5 minutes. Here is how not to.
I am conducting interviews now for Mid-Sr developers for an EU-based scale-up. I am absolutely amazed at how poorly candidates perform at a system design interview, and we have an absolutely run-of-the-mill exercise (not design your next Uber frontend and backend for 1 billion users).
The issue number one, which 90% fail at:
They follow no structure whatsoever.
The issue number two, which 80% fail at:
They do not get to understand the problem before designing.
There are different techniques/frameworks/steps for passing system design interviews, and I am just shocked that the candidates don't seem to follow any of them. All of this is readily available one Google search away (or one AI prompt if you wish). Classic example here. They all boil down to the following steps:
- Gather requirements.
- Estimate.
- High-level design.
- Deep-dive into selected area(s).
In the last step or afterward, there can be variations, and the conversation can go differently, which requires some practice. But the first three are ABSOLUTELY linear and straightforward. I will add one more critical piece of advice esp for Srs: explain your choices objectively and talk about trade-offs.