Coding (Platform)

Full-stack backend focus: Choose a safe refactoring boundary for cache boundary module boundary

A production rollout exposes a contract mismatch between the UI boundary and the owning service. The affected area is cache boundary.

Repair the cache boundary module boundary implementation so it ranks change-prone modules, preserves ownership boundaries, and identifies where characterization tests are required before extraction.

Evidence

Affected surface: Full-stack backend focus / cache boundary.
Observed failure family: choose a safe refactoring boundary.
Scope policy: retained must equal true.

What this task practices

This coding (platform) exercise trains the same sequence expected in an interview: understand the prompt, make assumptions explicit, produce a concrete answer, and explain the decisions behind it. The task is marked hard difficulty. The private workspace adds the tools required by this round, such as recording, code execution, diagrams, evidence panels, or structured notes. It also preserves the attempt so later feedback can be compared with previous work. Evaluation is based on task-specific criteria and the candidate seniority selected in the preparation path. Public pages never expose the reference solution, hidden tests, evaluator instructions, or another candidate’s work.