DevOps / SRE Engineer signal: hash map + dedupe in a blast-radius explorer context. This is a ProdMatch-owned devops sre drill, framed as a March 2026 Zerodha Service Reliability simulation, not a copied platform question.
Company context
Zerodha · Service Reliability
Freshness
March 2026
Product surface
blast-radius explorer
ProdMatch interview simulation based on product-team patterns; not a claim of a real company question.
For blast-radius explorer, collapse duplicate services by external ID. Keep the newest event per ID and return IDs in first-seen order.
Input
Output
Constraints
Concepts
[(a,1),(b,1),(a,3)] -> [(a,3),(b,1)]
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