Skip to content

Tracks Drills Topics Technologies Tech stacks Skill areas

Tracks Drills Guides

Loading

Aporeon

Technical interview practice, from one developer to another.

Guides About Editorial standards Support Privacy Terms Refund policy

Coding Practice - .NET Full Stack | Aporeon

.NET Full Stack

Coding Practice

Practical C# coding problems with examples, constraints, solutions, complexity, and edge-case thinking.

18 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 18

Practice this drill Choose another

Search

18 of 18 shown

1Word FrequencyRecommended startImplements a word-frequency counter with normalization, punctuation handling, and stable ordering.Coding problemEasy~15 min.NETC#Practice 2

Practice order

18 drillsOne at a time

1Word FrequencyUp next / Easy / ~15 min
2First Unique CharacterEasy / ~15 min
3Group OrdersMedium / ~25 min
4

First Unique Character

Implements 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

6Top K FrequentImplements top-K frequency selection with deterministic tie-breaking.Coding problemMedium~25 min.NETC#Practice

7Flatten Tree PathsFlattens a tree into display paths while preserving order and preventing simple cycles.Coding problemMedium~25 min.NETC#Practice

8Paged Result HelperImplements a safe in-memory paging helper with metadata and boundary handling.Coding problemEasy~15 min.NETC#Practice

9Parse FiltersParses a simple filter expression into a validated dictionary without accepting arbitrary keys.Coding problemMedium~25 min.NETC#Practice

10Date Range ValidationImplements a small validation helper for date ranges with clear error messages.Coding problemEasy~15 min.NETC#Practice

11Fixed Window LimiterImplements a small in-memory fixed-window rate limiter with per-key counters.Coding problemMedium~25 min.NETC#Practice

12Async Retry HelperImplements a bounded async retry helper that respects cancellation and does not retry every exception blindly.Coding problemHard~35 min.NETC#Practice

13LRU CacheImplements a small LRU cache using a dictionary plus linked list for O(1) get and put.Coding problemHard~35 min.NETC#Practice

14Error AggregationAggregates log entries into per-minute error counts with deterministic output.Coding problemMedium~25 min.NETC#Practice

15Compare dotted versionsCompare a deliberately simplified numeric dotted-version contract without claiming full SemVer 2.0 support.Coding problemMedium~25 min.NETC#Practice

16Invoice TotalImplements invoice total calculation with quantity, unit price, percentage discount, and rounding.Coding problemMedium~25 min.NETC#Practice

17Redact Log DataImplements safe redaction of known sensitive keys in a dictionary before logging.Coding problemMedium~25 min.NETC#Practice

18Batch ChunkingImplements chunking for batch processing without dropping final partial batches.Coding problemEasy~15 min.NETC#Practice

Dedupe Events

Medium / ~25 min

5Merge Time RangesMedium / ~25 min

6Top K FrequentMedium / ~25 min

7Flatten Tree PathsMedium / ~25 min

8Paged Result HelperEasy / ~15 min

+10 more drills in this section