System design (HLD) mock interviews
System design is the round that is hardest to practise alone. There is no test suite to tell you whether a design is right, only someone asking what happens when traffic grows ten times. On Practick that someone is another engineer, the hour is free, and the question comes from a bank of 600+ DSA and system design questions.
Book a free mock interviewYour interviewer reads an opening prompt, the same one you see on your screen, and from there it is your round. Sketch on any whiteboard you like (excalidraw.com works well) and share your screen in the call.
Your interviewer works from a guide written for that exact question: the answer to each clarifying question you might ask, the numbers to hand out when you ask for them, a ladder of follow-ups in the order to ask them, and a rubric that says what separates a mid level answer from a senior one.
Most questions list the companies they have been reported at, including Google, Amazon, Meta, Microsoft, Uber, Stripe, Flipkart, Swiggy and PhonePe.
Strong candidates work out the load before choosing an approach, pick a design that fits the numbers, and talk about trade offs without being asked. The rubric for each question lists those signals, and the red flags too: joining huge tables at read time, doing slow work inside the request, or ignoring an estimate made ten minutes earlier. Your feedback is written against it, so you know exactly what to fix.
If you are interviewing for a mid level, senior or staff role, expect at least one system design round and often two. New graduates sometimes get a lighter version. If your next loop has one, practise it with a person before it counts.
A few from the bank, with companies they have been reported at.
Yes. It uses the same credits as every other round: interview someone for an hour and you have earned an hour of your own. New accounts start with one free credit.
High level design (HLD) is about the system: services, data stores, queues, caches and how they scale. Low level design (LLD) is about classes and code structure inside one service. The system design track on Practick is HLD.
Any whiteboard works. Open one such as excalidraw.com in another tab and share your screen in the call, and your interviewer sees it live.
Yes. The question follows what you chose, and your interviewer gets a guide written for it: the prompt, the answers to your clarifying questions, the numbers, the follow-ups and the rubric. They do not need to have memorised the design.