Distributed Systems & System Design
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14 questions
Clear filtersQueues, Streams & Event Processing · Staff
The order exists. Why has the warehouse never heard about it?Atomic order creation cannot make broker publication atomic. A durable publication obligation, relay recovery, and source ordering solve a new boundary.
Queues, Streams & Event Processing · Staff
The warehouse processed the event. Why did it arrive again?Consumer offsets are progress markers, not proof of completed business effects. Atomic receipts and business identities defend separate races.
Queues, Streams & Event Processing · Staff
The replay worked. Why did it reserve stock again?Replay is a separate capability with permission boundaries, history completeness, and cutover conditions. It is not just a consumer group reset.
Queues, Streams & Event Processing · Senior
Publishing got faster. Why are urgent events arriving late?Choose producer batching policies by tracing buffering and end-to-end event freshness, including quiet-partition behavior.
Queues, Streams & Event Processing · Staff
We started 80 consumers. Why is one partition still two hours behind?Diagnose partition-level limits and per-key skew before claiming more consumer instances add throughput.
Queues, Streams & Event Processing · Staff
We quarantined the bad event. Which Kafka offset can we safely commit?Choose quarantine, repair and progress policy from per-key dependencies rather than applying a generic DLQ rule.
Queues, Streams & Event Processing · Staff
The consumer was down eight days. Where did day one go?Treat retention as a replay and recovery contract, distinguishing retained offsets from recoverable historical events.
Queues, Streams & Event Processing · Principal
One tenant published three times more. Why did every team slow down?Design end-to-end per-tenant quotas, admission and physical isolation while preserving other workloads under shared broker saturation.
Queues, Streams & Event Processing · Senior
Ten terabytes went into the job. Why is the shuffle taking longer than the scan?Explain the all-to-all exchange and distinguish input volume from shuffled bytes, with safe combinable pre-aggregation.
Queues, Streams & Event Processing · Staff
Nine hundred ninety-nine tasks finished. Why is the last one still running?Diagnose a slow executor versus one oversized key and select speculation or workload restructuring accordingly.
Queues, Streams & Event Processing · Staff
The lookup table was tiny. Why did the join move four terabytes?Choose distributed broadcast versus shuffle join from post-filter size, per-worker memory and source cardinality.
Queues, Streams & Event Processing · Staff
The dataset is only 200 GB. Why does opening it take longer than reading it?Explain why high file counts hurt planning and reads, and how snapshot-safe compaction and writer layout repair it.
Queues, Streams & Event Processing · Staff
Five hundred files were uploaded. Why can readers still see yesterday's table?Describe multi-file atomic visibility through immutable data, manifests and catalog compare-and-swap, including unknown commits.
Queues, Streams & Event Processing · Principal
Every pipeline task succeeded. Why is a week of revenue missing?Separate job success from semantic and business data correctness, gate publication, and recover through versioned lineage.