Practice Questions (Advanced)

Using Practice Exams

Practice exams serve two jobs: calibration and diagnosis. Take full-length, timed sets before studying domains — your first score tells you where the holes are and later scores measure real movement. Conditions matter: same time-per-question budget as the real exam, no pausing, no reference material. A relaxed untimed run measures recall; only a timed run measures exam performance.

Readiness looks like consistent scores in the mid-80s or above across multiple fresh sets, with misses scattered rather than clustered in one domain. One lucky 85% on a memorized set proves nothing; three honest 85%s across different sources is signal. Budget review time at least equal to the test time — the value is in the review, not the score.

Reviewing Every Miss

For each wrong answer, log four fields: the concept, why the chosen option felt right, why it is wrong, and the rule that decides it. This turns a miss into a durable rule — "regional RIs discount but reserve no capacity; zonal RIs do both" — instead of a remembered question.

Classify each error before moving on:

• Knowledge gap → read the service doc, then re-answer cold.
• Misread → annotate the stem; highlight constraint words (LEAST, FIRST, cost-effective).
• Trap → identify the distractor pattern: correct-but-overkill services, defaults over best practice.

Re-do missed items a week later without looking at notes. If it still fails, the rule never landed — re-derive it from the docs, not from the answer key.

Distractor Patterns

Certain answers are structurally wrong more often than others: options that introduce unnecessary complexity when a managed service fits; solutions that work technically but violate the stated constraint (cost, "least operational overhead"); absolutes like "always" and "never"; and hand-rolled systems where AWS offers a native feature.

Conversely, beware options that sound modern but mismatch the scenario — serverless for a steady-state high-throughput database, or multi-region active/active for a workload whose stated RTO is 24 hours. The correct answer consistently honors all constraints in the stem.

Practice reading stems backwards: cover the options, state your own answer, then match. It breaks the habit of picking the most familiar service name and trains constraint-first reasoning — the exact skill system-design interviews test.