The Interview Prep section tests whether you can reason about crossings under pressure, not whether you can recite them. It has four topics: a whiteboard framework that structures every answer, two assessed scenarios that put you in a realistic debug or review seat, and a Q&A bank for deliberate practice. Read this overview, then work the section itself with a whiteboard and a timer.
Every strong answer follows the same four parts: Assumption (classify the crossing or reset problem and state what you assume about the clocks and the protocol), Mechanism (explain how it works and how it fails), Trade-off (the fix or a bounded waiver, with cost and risk framing) and Evidence (the metric, the artifact and the regression and signoff criteria that show it is closed). The whiteboard framework topic teaches the sequence and the framework drills rehearse it until it is automatic. Examiners forgive a slow answer in this shape; they fail a fast answer without it.
Scenarios hand you a symptom and watch you work. Practice narrating out loud: what you would draw first, which question you would ask second, and where you would stop and escalate. The assessed scenarios are a metastability bug and a waiver debate, with further practice in the silicon metastability escape, the FIFO pointer mismatch, and the reset waiver crunch.
The Q&A bank, with its expanded set, grades answers as weak, better, or strong by level: a junior names the structure, a mid-level engineer adds the mechanism and the check, and a senior adds the evidence, the ownership, and the regression plan. The rubric behind every grade is mechanism, metric, evidence, ownership, decision, and regression. An answer missing any two is not yet senior, however confident it sounds.
Work the section in order: framework, then one scenario aloud with a timer, then the bank. Before scenarios, re-read the decision matrix, the waiver evidence template, and release order lessons so the facts are available when the pressure starts. Record yourself once: filler words and tool-name-dropping are audible only on replay.
Classify first: multi-bit word crossing, suspected tearing or reconvergence. Then mechanism, then the evidence you would request (report class, pointer or protocol state, waveforms) before naming any fix.