← Articulet System Design, Made Clear Spaced review
Retention layer Use after every chapter

Spaced review and mixed drills.

Do not let Chapter 6 feel clear today and disappear by Chapter 16.

Outcome
Retrieve old concepts at increasing intervals and mix them into new prompts so you can transfer ideas under interview pressure.
Schedule

The five-touch review rhythm.

T+0

End of chapter

Recall the memory hook, answer the practice prompt, and self-score one dimension.

T+1 day

Cold recall

Write the core idea from memory, then compare against the recap.

T+3 days

Fresh variation

Apply the idea to a different system without looking at the original chapter.

T+7 days

Mixed prompt

Combine this concept with one earlier concept and one later concept.

T+14 days

Mock transfer

Use the concept naturally inside a timed mock answer.

Mixed packs

Prompts that force transfer, not memorization.

After Part 1

Structure pack

  • Open a feed-design answer in 90 seconds.
  • Ask five clarifying questions, then remove two weak ones.
  • Recover from a missing requirement mid-answer.
After Part 2

Building-block pack

  • Choose database shape for URL mappings, user profiles, and messages.
  • Move one slow task off the request path.
  • Explain cache placement and invalidation risk.
After Part 3

Scale pack

  • Estimate reads, writes, peak, and storage for photo sharing.
  • Pick the first read bottleneck and first write bottleneck.
  • Name the strongest consistency guarantee required.
After Part 4

System transfer pack

  • Compare URL shortener and rate limiter correctness problems.
  • Compare chat and notification delivery semantics.
  • Explain which system needs async processing earliest.
Chapter habit

Use the compact block at the end of every chapter.

Every chapter now has a small training loop before the memory hook. Use it to recall, vary, and score rather than just read the model answer.

Recall

Say the chapter's core idea without looking. Then recall one related idea from an earlier chapter.

Vary

Change one constraint in the practice prompt and answer again in half the time.

Score

Use the rubric to pick one dimension below 3 and retry only that slice.