Graphshard70 minFrontend Engineer

Notifications Evidence Path Finder

Frontend Engineer signal: shortest path + weighted graph in a in-app notification tray context. This is a ProdMatch-owned frontend engineer drill, framed as a May 2026 Postman Engagement UX simulation, not a copied platform question.

Company context

Postman · Engagement UX

Freshness

May 2026

Product surface

in-app notification tray

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

Question

In in-app notification tray, 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

render scheduling
state graphs
virtualization
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?

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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

Timeline Dependency DAG Recoverymedium Timeline Evidence Path Finderhard Autocomplete Dependency DAG Recoveryhard