All six dimensions

Code reading

Most engineering time is spent reading, not writing. This dimension puts unfamiliar code in front of a candidate and asks what it does, what is wrong with it, and what depends on it.

What a candidate is asked to do

  1. 01Explain what a snippet does, including the case its author did not consider.
  2. 02Find the bug in code that looks correct at a glance.

How it is scored

What earns points

  • Tracing control flow accurately rather than pattern matching on names
  • Noticing the case the code silently mishandles
  • Reasoning about callers, not just the function in view

What loses points

  • Restating the code in prose without adding understanding
  • Confident claims about behaviour the code does not have

Why it predicts the job

An engineer who reads well is safe in a codebase they have never seen. An engineer who does not will rewrite something that already worked.

See code reading scored on a real assessment.