Graphshard70 minData Engineer

Lineage Dependency DAG Recovery

Data Engineer signal: topological sort + cycle detection in a data lineage graph context. This is a ProdMatch-owned data engineer drill, framed as a May 2026 SAP Labs Data Platform simulation, not a copied platform question.

Company context

SAP Labs · Data Platform

Freshness

May 2026

Product surface

data lineage graph

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

Question

You own data lineage graph for a Data Engineer loop. Given datasets and directed dependencies between them, return a valid execution order. If a cycle exists, return an empty list and identify that the rollout is blocked.

Input

n nodes labelled 0..n-1 and dependency pairs [before, after].

Output

A valid order of all nodes, or [] when dependencies contain a cycle.

Constraints

1 <= n <= 200000
0 <= dependencies.length <= 400000
The graph may be disconnected.

Concepts

stream windows
watermarks
lineage DAGs
topological sort
cycle detection
dependency graph

datasets: 4, deps: [[0,1],[0,2],[2,3]] -> [0,1,2,3] or [0,2,1,3]

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

Watermark Dependency DAG Recoverymedium Watermark Evidence Path Finderhard Lineage Evidence Path Findermedium