Game
GoF Patterns
A ticket lands and the code hurts. Read the story and the C# code, pick one of the 23 GoF patterns, and watch the architecture diagram get better or worse.
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Learn by playing
Games and quizzes for developers. Each one gives you real-looking problems, lets you make a call, and explains the answer, with links to the full articles on bool.dev.
Quiz
C# and .NET Interview Questions Quiz
Practice 1,234 C# and .NET interview questions with answers for Junior, Middle and Senior developers: C#, async, collections, ASP.NET Core, EF Core, SQL, microservices, testing, MAUI, AI and Agile. Timed mock interviews and progress tracking.
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Course
Big O Lab: Learn Big O Notation with C#
12 interactive lessons on time and space complexity, 113 C# questions on loops, recursion, .NET collections and LINQ, an algorithm race and a .NET Big O cheat sheet.
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Game
Hash Hotel: Hash Table Collision Game
Run the front desk of a hash table. Pick linear probing, quadratic probing, double hashing or chaining, fix a bad hash, choose when to resize and see why deletes need tombstones.
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Game
Hash Ring Tycoon: Consistent Hashing Game
Scale a cache fleet of 2,000 keys. See why key mod N reshuffles almost everything, then balance a consistent hash ring with virtual nodes and weighted servers.
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Game
Memo Siege: Memoization and Dynamic Programming Game
Repeated subproblems attack your castle. Place a limited number of caches on Fibonacci, grid paths, knapsack and edit distance and watch the recursion tree collapse.
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Simulator
Partition Chaos: Raft Consensus Simulator
You are the network for a 5-node Raft cluster. Kill the leader, split the cluster, lose quorum and watch leader election, log replication and commits react.
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Game
Pathfinding Duel: BFS, Dijkstra and A* Game
Draw a route by hand, then race BFS, Dijkstra, greedy best-first and A* on maps with mud, water and walls. Tune the heuristic and the A* weight.
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Soon
More coming soon
New games, quizzes and trainers are on the way. Until then, the blog has deep dives on the same topics.
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