The product page endpoint is the slowest thing we have. Someone suggests putting Redis in front of it. What do you want to know before agreeing?
Answer it out loud before you open anything. The value of the flags below is in comparing them to what you actually said.
The situation behind the question
An e-commerce catalogue. Product data changes when merchants edit listings, which they do all day. Traffic is heavily skewed towards a few hundred products, and there is a long tail of everything else.
What it is really testing
Whether a cache is a reasoned response to a measured access pattern or a reflex. The strongest candidates ask about the read/write ratio, key distribution and staleness tolerance before they ask about Redis, and know that a cache is a correctness liability bought with latency.