Top 3 Deduplication Interview Questions
Browse 3 real-world technical and behavioral interview questions about Deduplication. Review scenarios, edge cases, and architectural best practices.
Usage records arrive duplicated, late and out of order, and the tariff changed in the middle of the month. How does mediation and rating cope?
Mediation normalises and deduplicates records against a persisted key window sized to the worst observed lateness, then rating prices each record by its event time against an effective-dated tariff version. Prepaid is not merely faster postpaid; it reserves quota against a live balance.
Return every distinct triplet in the array that sums to zero.
Sort the array, fix each element as an anchor, then converge two pointers inwards from both ends of the remaining range. The sort is asymptotically free against the O of n squared scan, and it is what lets you skip duplicate values positionally instead of deduplicating a set of results afterwards. It also connects sorting to the point an interviewer is testing.
Two people are typing in the same chat and one is on a train. What arrives, in what order, and what do you store?
Chat ordering with offline clients separates ephemeral typing indicators from durable messages. Messages need a server-assigned per-conversation sequence and a client-generated id for deduplication, so reconnecting phones replay outboxes without duplicates.