Job-Ready Coding Lab Pro

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JR-INT-101foundation

Deduplicate a global event stream

A multi-region service retries delivery. Interviewers want a small, correct function before discussing the distributed version.

GoogleMetaAmazon

YOUR TASK

Return the first event for each non-empty id, preserving arrival order. Collect invalid record indexes without mutating the input.

Acceptance checks

hash mapsstable orderinput validation

35 minute target North America · Europe · APAC

solution.jsJavaScript · local convenience runner

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Test output

Run the visible regression checks when you are ready. This browser convenience runner is not a security sandbox or trusted CTF score.