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Checkpoint: Concurrency

advanced30 min readLesson 125 of 169

The checkpoint asks for the retry loop done RIGHT: resubmitted futures must be awaited.

Checkpoint — concurrent job processor (hardened)

Same contract as the project: run_jobs(jobs, workers=3, retries=2) returns {'succeeded': {index: value}, 'failed': [sorted indices]}, retrying failures up to retries extra attempts.

This checkpoint's extra scrutiny: every submitted future's outcome must be observed. A resubmitted retry that nobody awaits loses its result and its exception — a real production bug. The wrong-solution probe fires exactly this mistake.