#Question bank

Questions cluster into about eight shapes. Recognising the shape is most of the work — once you know a prompt is "fan-out with a hot-key problem", the derivation is familiar even if the domain is new.

#1 · The eight shapes

When you get an unfamiliar prompt, classify it first. "This is essentially a fan-out problem with a hot-key case" both orients you and shows the interviewer you are reasoning from structure.

#2 · The prompts

#Read-heavy key lookup

#Fan-out

#Connection-oriented

#Strong consistency

#Large media

#Crawl / ingest

#Search / ranking

#Geospatial

#Infrastructure

#3 · Fifteen to actually do

In this order. Each adds something the previous ones did not.

The bolded six cover most of the shape space. If you only do six, do those.

#4 · A four-week schedule

Week 1 — the method

Week 2 — blocks and the canonical designs

Week 3 — the hard parts

Week 4 — fluency

#5 · How to practise alone

Rehearsal has to look like the round or it does not transfer.

[ ] Set a 45-minute timer. Do not pause it.
[ ] Stand at a whiteboard or use a blank digital canvas. Not an editor.
[ ] Speak out loud the entire time. Record yourself.
[ ] Do NOT look anything up mid-design.
[ ] Afterwards, listen back and mark:
      - did you scope before designing?
      - did an estimate change a decision?
      - can you trace each choice to a requirement?
      - did you go three levels deep anywhere?
      - did you volunteer a weakness?
      - how much dead silence?

Listening back is uncomfortable and it is the highest-value thirty minutes in the whole schedule. You will hear filler, hedging, and unjustified choices that you had no idea were there.

Then read the write-up and mark only where you differed and why. Places you matched teach nothing.

#6 · Judging yourself