Graphshard70 minPlatform Engineer

CI Evidence Path Finder

Platform Engineer signal: shortest path + weighted graph in a CI flake detector context. This is a ProdMatch-owned platform engineer drill, framed as a May 2026 PolicyBazaar Engineering Productivity simulation, not a copied platform question.

Company context

PolicyBazaar · Engineering Productivity

Freshness

May 2026

Product surface

CI flake detector

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

Question

In CI flake detector, 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

build DAGs
tenant quotas
artifact caching
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

Build Dependency DAG Recoverymedium Build Evidence Path Finderhard Artifacts Dependency DAG Recoveryhard