Vibe codingHardvc-g185

Subject Ai code reviewLevel Senior–Staff~22 minCommon in Distributed systems interviewsIndustries Software development, Technology

Question

An AI built this Java Kafka consumer that applies account state-change events. It parallelizes processing across a thread pool for throughput. Review the ordering assumptions.

java

1void onRecords(ConsumerRecords<String, Event> records) {2    for (ConsumerRecord<String, Event> rec : records) {3        executor.submit(() -> {4            Account a = repo.load(rec.value().accountId());5            a.apply(rec.value());      // e.g. SET_STATUS, then later DELETE6            repo.save(a);7        });8    }9    consumer.commitSync();   // commit after dispatching10}

What correctness bug does the parallelism introduce, and what's the safe design?

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