System design mock interviews
A system design round has no right answer, which is exactly what makes it hard to practise alone. The score comes from how you narrow an open question and which trade-offs you make on purpose.
AI rounds from ₹49 · Live mocks with a working engineer from ₹999 · Pay per session
What a System design round covers
Scoping the question
Turning "design X" into something answerable: who uses it, how much, and what you are explicitly not building. Candidates who skip this end up designing the wrong system well.
Data model and access patterns
What you store, how it is read, and which access pattern drives the choice. Storage decisions made before the read pattern is known are the usual first wrong turn.
Scaling and bottlenecks
Where it breaks first as traffic grows, and what you would measure to know. Naming the bottleneck before adding a cache is the difference between reasoning and pattern-matching.
Trade-offs and failure
Consistency against availability, what degrades when a component fails, and what you chose to accept. This is where senior candidates separate themselves.
What the interviewer is listening for
The strongest signal is deliberate narrowing: stating what you are optimising for, then designing for it. Reciting a reference architecture without connecting it to the requirements reads as memorisation and is followed up hard.
Where candidates lose marks
- Jumping to boxes and arrows before agreeing what the system must do.
- Adding a cache, a queue and a shard without saying what each solves.
- Presenting one design as correct and never naming the alternative you rejected.
Two ways to practise
An AI round, on your own
One question at a time with real follow-ups on what you actually said. Choose three, five or eight questions. Scored the moment you finish, with a written breakdown across technical depth, problem solving and communication.
A live mock with an engineer
Forty minutes over Zoom with someone who runs system design interviews for a living. They score five criteria and write up what to fix, and you keep a numbered certificate for the session.
Other tracks
Not sure which to book? The FAQ covers how sessions are scored, and candidate stories show what people did with the feedback.