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Aporeon

Technical interview practice, from one developer to another.

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C# Practical Coding Problems

Strings & Collections

Word counts, unique characters, grouping, dedupe, and interval-style collection problems.

5 drillsPractice one at a timeOrdered pathCoding problem

Recommended start

Word Frequency

Implements a word-frequency counter with normalization, punctuation handling, and stable ordering.

Easy~15 minStep 1 of 5

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1Word FrequencyRecommended startImplements a word-frequency counter with normalization, punctuation handling, and stable ordering.Coding problemEasy~15 min.NETC#Practice 2First Unique CharacterImplements a stable first-unique-character search using counts and original order.Coding problemEasy~15 min.NETC#Practice 3Group OrdersBuilds customer summaries from order rows using grouping, aggregation, and deterministic ordering.Coding problemMedium~25 min.NETC#Practice 4Dedupe EventsImplements duplicate suppression while preserving the first event for each idempotency key.Coding problemMedium~25 min.NETC#Practice 5Merge Time RangesImplements interval merging for scheduling-style time ranges with sorted output.Coding problemMedium~25 min.NETC#Practice

Practice order

5 drillsOne at a time

1Word FrequencyUp next / Easy / ~15 min
2First Unique CharacterEasy / ~15 min
3Group OrdersMedium / ~25 min
4Dedupe EventsMedium / ~25 min
5Merge Time RangesMedium / ~25 min