Public question and preparation brief

Difficulty

Intermediate

Time

45–60 min

Stage 01

Fix the contract

State the operations, the access pattern you are designing for, and the complexity you promise for each. Say which guarantee you would relax first if the workload changed.

What to demonstrate: Are the promised properties explicit enough to test?

Stage 02

Choose the representation

Describe the structure that keeps indexed reads cheap while mutations continue, and name the extra cost it accepts in exchange.

What to demonstrate: Can the candidate defend a trade-off instead of merely naming a familiar data structure?

Stage 03

Write a checkpoint

Define what a checkpoint contains and how it is written so that a crash leaves either the previous state or the new one. Then explain what restart does with a checkpoint that was only partly written.

What to demonstrate: Is the atomicity claim specific about write ordering and how partial work is detected?

Stage 04

Prove the restart

List the crash points you would inject during a checkpoint and the invariants you would assert after each restart.

What to demonstrate: Can the candidate turn a durability claim into an executable test?