Intervalshard70 minPlatform Engineer

CI Capacity Interval Planner

Platform Engineer signal: line sweep + interval merge in a CI flake detector context. This is a ProdMatch-owned platform engineer drill, framed as a April 2026 Postman Engineering Productivity simulation, not a copied platform question.

Company context

Postman · Engineering Productivity

Freshness

April 2026

Product surface

CI flake detector

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

Question

Plan capacity for CI flake detector. Given reservation intervals with requested units, return the minimum capacity needed and all time ranges where capacity crosses a critical threshold.

Input

Intervals [start, end, units] and threshold.

Output

Peak capacity and merged high-pressure intervals.

Constraints

1 <= intervals.length <= 200000
Intervals are half-open: [start, end).
Timestamps fit in signed 32-bit integers.

Concepts

build DAGs
tenant quotas
artifact caching
line sweep
interval merge
capacity planning

[[1,4,3],[2,5,4]], threshold=6 -> peak=7, hot=[[2,4]]

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

Be explicit about whether touching endpoints overlap.
Process end events before start events for half-open intervals.

Next Similar Problems

Build Capacity Interval Plannerhard Artifacts Capacity Interval Plannerhard Tenancy Capacity Interval Plannerhard