Place 2 cuts to balance the load across 3 shards.

Keys sit in order with different weights; cuts split them into contiguous ranges. Balance the load, not the key count — equal-sized ranges hotspot when the data is skewed.

Practice — no rating pressure. Get as close to the optimum as you can; each play teaches the pattern.

Busiest shard

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0 / 2 cuts

tap the gaps to cut · shard loads: 70

The Shard — practice the decision, scored against the optimum

What does the The Shard puzzle teach?

Range-shard by load, not by key count — equal-sized ranges hotspot when the data is skewed.

Why do interviews ask about this?

Partitioning to balance load is the sharding interview: minimize the hottest shard, not just split evenly.

How is it scored?

The engine computes the provably-optimal answer for the exact instance you played (dynamic programming, shortest-path, or exhaustive search — never a heuristic) and scores your attempt as a percentage of it. No login needed to see your score.

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Practice0:00

The Shard · D1

Place 2 cuts to balance the load across 3 shards.

Keys sit in order with different weights; cuts split them into contiguous ranges. Balance the load, not the key count — equal-sized ranges hotspot when the data is skewed.

Practice — no rating pressure. Get as close to the optimum as you can; each play teaches the pattern.

Busiest shard

—

0 / 2 cuts

tap the gaps to cut · shard loads: 70