Flipkart Software Development Engineer II interview questions

So, here it goes: First Round - Machine Coding round. Asked to design a multi layered cache. (L1, L2 and L3). The question wasn't difficult but the problem lies in their explanation. First, they want the functionality should be completely demoed . The time given is 1.5 hours. Now they expect the functionality, scalable and design patterns implemented. Isn't that too less time for this type of question. What I see the problem is they need to differentiate properly between HLD and LLD questions.