Sliding Windowhard70 minData Engineer

Schema Streaming Window Anomaly

Data Engineer signal: sliding window + frequency map in a schema evolution context. This is a ProdMatch-owned data engineer drill, framed as a March 2026 CleverTap Data Contracts simulation, not a copied platform question.

Company context

CleverTap · Data Contracts

Freshness

March 2026

Product surface

schema evolution

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

Question

For schema evolution, process a timestamp-ordered stream of versions. Find the longest contiguous window where at most k distinct risk labels appear and the total severity stays under budget.

Input

Array of events {label, severity} and integers k, budget.

Output

Maximum window length satisfying both constraints.

Constraints

1 <= events.length <= 300000
1 <= k <= 50
Severity values are positive integers.

Concepts

stream windows
watermarks
lineage DAGs
sliding window
frequency map
stream processing

labels: A,B,A,C with k=2 and budget=7 -> longest valid window length is 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?

Your rating tunes when this problem shows up again.

Common Mistakes

Update the answer only after the window is valid.
Avoid recomputing the whole window on every move.

Next Similar Problems

Watermark Streaming Window Anomalyhard Lineage Streaming Window Anomalyhard Dedupe Streaming Window Anomalyhard