Spread 8 requests across 3 servers — keep the busiest server lowest.

Tap a request to move it to the next server. The tallest column is the makespan — minimise it. Round-robin spreads by count, not load; place the heaviest requests with care.

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

srv 133

srv 239

srv 339

makespan 39 · tap a request to rebalance

The Balancer — practice the decision, scored against the optimum

What does the The Balancer puzzle teach?

Minimising the busiest server's load is multiprocessor scheduling — place the heaviest requests first, not round-robin.

Why do interviews ask about this?

Load balancing / makespan is the “how do you distribute work” interview: minimize the busiest server, not the average.

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 Balancer · D1

Spread 8 requests across 3 servers — keep the busiest server lowest.

Tap a request to move it to the next server. The tallest column is the makespan — minimise it. Round-robin spreads by count, not load; place the heaviest requests with care.

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

srv 133

srv 239

srv 339

makespan 39 · tap a request to rebalance