Practical field notes on C#, .NET performance, EF Core, software architecture, security, testing, and deliberate practice.https://katabench.com/en-ushttps://katabench.com/blog/aspire-service-discoveryhttps://katabench.com/blog/aspire-service-discoveryLearn how Aspire service discovery turns logical names into endpoints with WithReference, HttpClient resolution, health checks, and replica load balancing.Sun, 09 Aug 2026 00:00:00 GMTArchitecture & DesignThe Katabench teamhttps://katabench.com/blog/circuit-breaker-pattern-dotnethttps://katabench.com/blog/circuit-breaker-pattern-dotnetBuild a circuit breaker in modern .NET with Polly and HttpClient resilience. Tune the failure window, compose retries safely, and prove recovery.Sun, 09 Aug 2026 00:00:00 GMTArchitecture & DesignThe Katabench teamhttps://katabench.com/blog/message-queue-vs-event-bushttps://katabench.com/blog/message-queue-vs-event-busCompare message queues, event buses, and pub/sub by delivery topology. Choose competing workers or fan-out, then design retries and ordering honestly.Sun, 09 Aug 2026 00:00:00 GMTArchitecture & DesignThe Katabench teamhttps://katabench.com/blog/mutation-testing-csharphttps://katabench.com/blog/mutation-testing-csharpMutation testing in C# plants controlled bugs and asks whether your tests notice. Learn Stryker.NET, triage survivors, and set useful CI gates.Sun, 09 Aug 2026 00:00:00 GMTTesting & RefactoringThe Katabench teamhttps://katabench.com/blog/path-traversal-aspnet-corehttps://katabench.com/blog/path-traversal-aspnet-coreA path traversal vulnerability lets user input escape a trusted directory. See the unsafe C# patterns, the containment check, and tests that prove it.Sun, 09 Aug 2026 00:00:00 GMTSecurity & ReliabilityThe Katabench teamhttps://katabench.com/blog/string-concatenation-performance-csharphttps://katabench.com/blog/string-concatenation-performance-csharpChoose between +, interpolation, StringBuilder, and direct writes in modern C#. Fix repeated copying, then verify the result with allocation benchmarks.Sun, 09 Aug 2026 00:00:00 GMT.NET PerformanceThe Katabench teamhttps://katabench.com/blog/structured-logging-dotnethttps://katabench.com/blog/structured-logging-dotnetLearn structured logging in .NET with ILogger message templates, named fields, scopes, correlation IDs, safe data handling, and query-first design.Sun, 09 Aug 2026 00:00:00 GMTArchitecture & DesignThe Katabench teamhttps://katabench.com/blog/cancellation-token-aspnet-corehttps://katabench.com/blog/cancellation-token-aspnet-coreA disconnected client does not make your database query disappear. Learn how RequestAborted flows through ASP.NET Core, EF Core, and HttpClient, where cancellation should stop, and how to test it.Sun, 02 Aug 2026 00:00:00 GMT.NET PerformanceThe Katabench teamhttps://katabench.com/blog/transactional-outbox-dotnethttps://katabench.com/blog/transactional-outbox-dotnetSaving data and publishing an event are two writes that can disagree. Build a transactional outbox with EF Core, a retrying publisher, and idempotent consumers so crashes do not lose business events.Thu, 30 Jul 2026 00:00:00 GMTArchitecture & DesignThe Katabench teamhttps://katabench.com/blog/optimistic-concurrency-ef-corehttps://katabench.com/blog/optimistic-concurrency-ef-coreTwo users edit the same row and the last save silently wins. Use EF Core concurrency tokens, inspect the generated UPDATE, handle DbUpdateConcurrencyException, and test the race with two DbContexts.Mon, 27 Jul 2026 00:00:00 GMTDatabases & EF CoreThe Katabench teamhttps://katabench.com/blog/addsingleton-vs-addscoped-vs-addtransienthttps://katabench.com/blog/addsingleton-vs-addscoped-vs-addtransientAddSingleton vs AddScoped vs AddTransient in plain terms: what each lifetime promises, sensible defaults, and the captive dependency bug that ships.Thu, 16 Jul 2026 00:00:00 GMTArchitecture & DesignThe Katabench teamhttps://katabench.com/blog/async-await-mistakes-csharphttps://katabench.com/blog/async-await-mistakes-csharpThe C# async await mistakes that pass code review: async void, fire and forget tasks, missing CancellationToken plumbing, and blocking on .Result.Thu, 16 Jul 2026 00:00:00 GMT.NET PerformanceThe Katabench teamhttps://katabench.com/blog/caching-strategieshttps://katabench.com/blog/caching-strategiesCaching strategies from the cache-aside flow to the hard parts: invalidation owned by a human and stampedes tamed by single-flight and jitter.Thu, 16 Jul 2026 00:00:00 GMTArchitecture & DesignThe Katabench teamhttps://katabench.com/blog/code-smells-csharphttps://katabench.com/blog/code-smells-csharpCode smells are symptoms, not verdicts. Six worth knowing, with C# examples: the tell for each, why it hurts, and the refactoring move that clears it.Thu, 16 Jul 2026 00:00:00 GMTTesting & RefactoringThe Katabench teamhttps://katabench.com/blog/connection-poolinghttps://katabench.com/blog/connection-poolingConnection pooling explained from the failure end: what a connection costs, the three ways pools drain, and why the timeout blames the wrong request.Thu, 16 Jul 2026 00:00:00 GMTDatabases & EF CoreThe Katabench teamhttps://katabench.com/blog/cyclomatic-complexityhttps://katabench.com/blog/cyclomatic-complexityCyclomatic complexity counts the independent paths through a method. How to compute it by eye, what a score of 10 predicts, and how to reduce it for real.Thu, 16 Jul 2026 00:00:00 GMTTesting & RefactoringThe Katabench teamhttps://katabench.com/blog/dotnet-garbage-collection-explainedhttps://katabench.com/blog/dotnet-garbage-collection-explained.NET garbage collection explained: why most objects die young, what gen 0, 1, and 2 collections cost, and why the large object heap hurts latency.Thu, 16 Jul 2026 00:00:00 GMT.NET PerformanceThe Katabench teamhttps://katabench.com/blog/how-database-indexes-workhttps://katabench.com/blog/how-database-indexes-workHow do database indexes work? A B-tree is a small sorted structure with huge fanout, so a lookup reads a handful of pages instead of the whole table.Thu, 16 Jul 2026 00:00:00 GMTDatabases & EF CoreThe Katabench teamhttps://katabench.com/blog/idempotency-api-designhttps://katabench.com/blog/idempotency-api-designEvery serious client retries. How the idempotency key pattern and a database unique constraint keep a retried payment from becoming two charges.Thu, 16 Jul 2026 00:00:00 GMTSecurity & ReliabilityThe Katabench teamhttps://katabench.com/blog/rate-limiting-algorithmshttps://katabench.com/blog/rate-limiting-algorithmsRate limiting algorithms compared: why fixed windows leak double the limit, how token buckets forgive bursts, and what a good 429 response returns.Thu, 16 Jul 2026 00:00:00 GMTSecurity & ReliabilityThe Katabench teamhttps://katabench.com/blog/unit-testing-best-practiceshttps://katabench.com/blog/unit-testing-best-practicesUnit testing best practices that survive refactoring: AAA structure, behavior-first assertions, a healthy test pyramid, and determinism over flakiness.Thu, 16 Jul 2026 00:00:00 GMTTesting & RefactoringThe Katabench teamhttps://katabench.com/blog/primitive-obsession-value-objectshttps://katabench.com/blog/primitive-obsession-value-objectsWhen everything is a string, a decimal, or a Guid, the type system can't tell your arguments apart. Value objects in modern C#, the bugs they delete, and when they're overkill.Sun, 12 Jul 2026 00:00:00 GMTTesting & RefactoringThe Katabench teamhttps://katabench.com/blog/sync-over-asynchttps://katabench.com/blog/sync-over-asyncLearn how sync over async causes .NET Thread Pool starvation, spot it with dotnet-counters, capture blocking stacks, and fix ASP.NET Core latency.Sat, 11 Jul 2026 00:00:00 GMT.NET PerformanceThe Katabench teamhttps://katabench.com/blog/offset-vs-keyset-paginationhttps://katabench.com/blog/offset-vs-keyset-paginationOFFSET pagination reads every row it skips, so page 2,000 costs 2,000 pages of work. Keyset pagination seeks straight to the next page. The SQL, the EF Core, the trade-offs.Fri, 10 Jul 2026 00:00:00 GMTDatabases & EF CoreThe Katabench teamhttps://katabench.com/blog/multiple-enumeration-linqhttps://katabench.com/blog/multiple-enumeration-linqAn IEnumerable isn't a list; it's a promise to do work later. Enumerate it twice and the work happens twice, including, with EF Core, the database query.Thu, 09 Jul 2026 00:00:00 GMT.NET PerformanceThe Katabench teamhttps://katabench.com/blog/redos-catastrophic-backtrackinghttps://katabench.com/blog/redos-catastrophic-backtrackingCatastrophic backtracking turns an email regex into a denial of service: 30 characters, nearly a minute of CPU. Why nested quantifiers explode and how .NET lets you defuse them.Wed, 08 Jul 2026 00:00:00 GMTSecurity & ReliabilityThe Katabench teamhttps://katabench.com/blog/tutorial-hellhttps://katabench.com/blog/tutorial-hellWatching code get written trains recognition, not recall. Why tutorials feel like progress, why the skill doesn't transfer, and how to build a loop that does.Tue, 07 Jul 2026 00:00:00 GMTEngineering PracticeThe Katabench teamhttps://katabench.com/blog/coding-interviews-vs-real-skillhttps://katabench.com/blog/coding-interviews-vs-real-skillWhiteboard interviews measure the wrong slice of engineering. The case for practicing what predicts a good engineer: correct, fast, well-structured, secure code.Thu, 25 Jun 2026 00:00:00 GMTEngineering PracticeThe Katabench teamhttps://katabench.com/blog/owasp-top-10-csharphttps://katabench.com/blog/owasp-top-10-csharpA practical tour of the OWASP Top 10 for .NET developers: the ASP.NET Core and EF Core patterns behind broken access control, injection, SSRF, and overposting.Wed, 24 Jun 2026 00:00:00 GMTSecurity & ReliabilityThe Katabench teamhttps://katabench.com/blog/sql-injection-still-alivehttps://katabench.com/blog/sql-injection-still-aliveSQL injection is supposedly solved, yet it's still in the OWASP Top 10. The C# patterns that keep it alive in EF Core and ADO.NET, and how to kill them.Mon, 22 Jun 2026 00:00:00 GMTSecurity & ReliabilityThe Katabench teamhttps://katabench.com/blog/architecture-fitness-functionshttps://katabench.com/blog/architecture-fitness-functionsArchitecture decays because nothing fails the build when the domain references the DbContext. Fitness functions with ArchUnitNET assert layering and dependency rules in CI like any test.Sat, 20 Jun 2026 00:00:00 GMTArchitecture & DesignThe Katabench teamhttps://katabench.com/blog/hexagonal-architecture-dotnethttps://katabench.com/blog/hexagonal-architecture-dotnetPorts and adapters explained in plain C#: domain in the center, ports as interfaces, adapters as infrastructure. Why it beats layered spaghetti, and when it is overkill for a CRUD app.Thu, 18 Jun 2026 00:00:00 GMTArchitecture & DesignThe Katabench teamhttps://katabench.com/blog/dependency-inversion-csharphttps://katabench.com/blog/dependency-inversion-csharpThe D in SOLID is the most quoted and least applied principle. Dependency inversion means depending on abstractions you own and pointing dependencies inward, not registering services.Tue, 16 Jun 2026 00:00:00 GMTArchitecture & DesignThe Katabench teamhttps://katabench.com/blog/refactoring-legacy-csharphttps://katabench.com/blog/refactoring-legacy-csharpHow to refactor legacy C# without breaking it: write characterization tests first, then take small behavior-preserving steps (extract method, introduce a seam, replace conditional with polymorphism).Sat, 13 Jun 2026 00:00:00 GMTTesting & RefactoringThe Katabench teamhttps://katabench.com/blog/green-checkmarks-liehttps://katabench.com/blog/green-checkmarks-lieA green check can prove output without proving the solution scales. Learn how performance, allocation, query, and structure gates turn a result into actionable feedback.Wed, 10 Jun 2026 00:00:00 GMTEngineering PracticeThe Katabench teamhttps://katabench.com/blog/measuring-code-qualityhttps://katabench.com/blog/measuring-code-qualityFour code quality metrics you can actually automate in C#: cyclomatic complexity, nesting depth, method length, and duplication, with reasonable thresholds and a refactor that passes them.Mon, 08 Jun 2026 00:00:00 GMTTesting & RefactoringThe Katabench teamhttps://katabench.com/blog/ef-core-performance-habitshttps://katabench.com/blog/ef-core-performance-habitsNine EF Core habits that pass every test and quietly tank performance in production: missing AsNoTracking, fetching whole entities, N+1, cartesian explosion, counting in memory, and more.Tue, 02 Jun 2026 00:00:00 GMTDatabases & EF CoreThe Katabench teamhttps://katabench.com/blog/ef-core-query-plans-indexeshttps://katabench.com/blog/ef-core-query-plans-indexesA perfectly written EF Core query can still do a sequential scan: no index, or a function on a column makes it non-sargable. How to read a query plan and fix it.Tue, 26 May 2026 00:00:00 GMTDatabases & EF CoreThe Katabench teamhttps://katabench.com/blog/iqueryable-vs-ienumerablehttps://katabench.com/blog/iqueryable-vs-ienumerableReturning IEnumerable, or calling ToList too early, moves filtering and paging into C# memory. How one type change turns an indexed WHERE into loading a million rows.Tue, 19 May 2026 00:00:00 GMTDatabases & EF CoreThe Katabench teamhttps://katabench.com/blog/ef-core-n-plus-1https://katabench.com/blog/ef-core-n-plus-1An EF Core loop that looks innocent fires one query per row. It passes every unit test and dies in production. How N+1 happens, the SQL it generates, and the fix.Tue, 12 May 2026 00:00:00 GMTDatabases & EF CoreThe Katabench teamhttps://katabench.com/blog/deliberate-practice-programmershttps://katabench.com/blog/deliberate-practice-programmersRepetition doesn't make you better; deliberate practice does. It needs immediate, specific feedback at the edge of your ability, and most coding practice fails that test badly.Tue, 05 May 2026 00:00:00 GMTEngineering PracticeThe Katabench teamhttps://katabench.com/blog/how-seniors-practicehttps://katabench.com/blog/how-seniors-practiceIt isn't grinding more LeetCode for correctness. Seniors practice the things production grades: performance, data-access shape, design, and security. Here's the difference.Tue, 28 Apr 2026 00:00:00 GMTEngineering PracticeThe Katabench teamhttps://katabench.com/blog/premature-optimization-mythhttps://katabench.com/blog/premature-optimization-mythThe most-abused quote in software lets developers dodge thinking about performance entirely. Here's Knuth's real argument, and why finding the 3% requires an instinct you have to train.Tue, 21 Apr 2026 00:00:00 GMT.NET PerformanceThe Katabench teamhttps://katabench.com/blog/span-memory-zero-allocationhttps://katabench.com/blog/span-memory-zero-allocationSpan<T> and stackalloc let you parse and slice without allocating, but they have real limits. Here's when zero-allocation C# earns its keep and when it's overkill.Thu, 09 Apr 2026 00:00:00 GMT.NET PerformanceThe Katabench teamhttps://katabench.com/blog/dotnet-allocationshttps://katabench.com/blog/dotnet-allocationsIn .NET, correct and algorithmically optimal code can still drag, because every needless allocation feeds the GC. Here's how to spot and cut allocation pressure in C#.Tue, 31 Mar 2026 00:00:00 GMT.NET PerformanceThe Katabench teamhttps://katabench.com/blog/big-o-in-productionhttps://katabench.com/blog/big-o-in-productionBig-O gets crammed for interviews and forgotten. But quadratic C# passes your tests and melts in prod. Here's where it bites and how to make complexity an instinct.Wed, 18 Mar 2026 00:00:00 GMT.NET PerformanceThe Katabench team