Debug a Round-Robin Load Balancer, Then Implement Consistent Hashing
Company: DoorDash
Role: Software Engineer
Category: Software Engineering Fundamentals
Difficulty: medium
Interview Round: Onsite
Overview: Debug a round-robin load balancer that must keep strict rotation while servers are added and removed, then implement a consistent-hash ring that gives each key a stable server. It tests off-by-one and index-mutation bugs, thread safety, stable hashing, virtual nodes, lookup cost, and how many keys move on membership changes.
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