Interview framework: free-recall review
Free-recall prompts across the interview-framework unit. Reconstruct each step of the procedure in your own words — requirements, estimation, HLD and deep-dive, bottlenecks and tradeoffs — before revealing the model answer.
Retrieval beats re-reading. For each prompt, say or write a full answer from memory — the step of the procedure and the reasoning behind it — before you open the model answer. Reconstructing the framework is what turns it from notes you’ve read into a procedure you can run live at the whiteboard.
Reconstruct the whole framework without looking back: what you clarify before drawing, which number you estimate and why, how you split a clean HLD from a real deep-dive, how you find the binding bottleneck, and how you name a tradeoff with its price.
- 01What do you clarify before drawing any box, and why are the non-functional requirements where the design is decided?
- 02Which numbers do you estimate in the interview, and what's the rule for when a number belongs on the whiteboard?
- 03What does the HLD prove, what does the deep-dive prove, and how do you choose what to deep-dive?
- 04How do you find the bottleneck, and why does average utilization lie about it?
- 05Name the recurring tradeoff axes, how you handle '10×', and what separates a senior answer from a mid one.
If you could reconstruct each answer from memory, you hold the framework as a runnable procedure. Requirements: split functional from non-functional (the latter, as numbers, decide the design), scope the prompt, name entities and their access patterns. Estimation: compute only the numbers that change the design — peak read/write QPS, storage by class, hot set, bandwidth — sized for the peak, read to one significant figure, calibrated to whether the interviewer wants math or conclusion. HLD and deep-dive: compose the justified skeleton fast, then engineer the one or two genuinely hard components deeply (announce the choice; depth beats breadth). Bottlenecks and tradeoffs: find the single hottest resource the average hides, handle “10×” by recomputing and naming the new binding resource, and state every choice as a deliberate tradeoff with its price. The thread tying them together is the seniority signal: name the specific resource and the cost of each decision, never just “add more servers.”
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