Graphshard70 minDevOps / SRE Engineer

OnCall Evidence Path Finder

DevOps / SRE Engineer signal: shortest path + weighted graph in a on-call routing context. This is a ProdMatch-owned devops sre drill, framed as a May 2026 Arcesium Incident Response simulation, not a copied platform question.

Company context

Arcesium · Incident Response

Freshness

May 2026

Product surface

on-call routing

ProdMatch interview simulation based on product-team patterns; not a claim of a real company question.

Question

In on-call routing, entities are connected by weighted evidence edges. For each query, find the least-cost evidence path from source to target while avoiding blocked entities.

Input

Weighted graph, blocked set, and q source-target queries.

Output

Minimum cost per query, or -1 if unreachable.

Constraints

1 <= nodes <= 100000
1 <= edges <= 300000
1 <= queries <= 100000
All weights are non-negative.

Concepts

blast-radius graphs
alert dedupe
rolling windows
shortest path
weighted graph
retrieval quality

0-1 cost 2, 1-2 cost 3, query 0->2 -> 5

Approach

Try framing your own approach first. The 30 seconds you think before peeking is where learning happens.

Clean Solution

Reveal the approach first.

How well did you understand?

Your rating tunes when this problem shows up again.

Common Mistakes

Mark visited when enqueueing, not after repeated dequeue.
Do not ignore disconnected components if the product surface can have them.

Next Similar Problems

Incident Dependency DAG Recoverymedium Incident Evidence Path Finderhard Deploy Dependency DAG Recoveryhard