Editor's note
I pulled a deliberately mixed lineup this time: EF Core LINQ behavior, C# 14 null handling, performance tuning, and a few workflow pieces. The cache deep dive and the route-constraints guide stood out for being immediately useful in real projects, not just academically interesting.
EF Core, C# 14 and performance fixes
Jasen Fici
December 30, 2025
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Today's Articles
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Jasen's take on today's picks
When Static Validations No Longer Have Power
A reconfigurable validation approach that uses compiled expressions when static rules stop being enough.
EF Core + LINQ: The Real-World Guide Every C# Developer Wishes They Had Earlier
A practical EF Core and LINQ guide that focuses on real-world query behavior instead of textbook examples.
ToList() vs ToArray() in C#: The Performance Guide Every Developer Needs
A memory-minded comparison of ToList() and ToArray() that makes the tradeoffs easy to apply.
A clear DTO refresher that should help anyone cleaning up API boundaries or payload shape.
Understanding .NET Application Lifecycles: From Startup to Shutdown
A lifecycle walkthrough that’s useful when you need to reason about startup, shutdown, and app behavior.
Build, Rebuild, and Clean Solution — Explained Like You Actually Need It
A Visual Studio explainer that demystifies Build, Rebuild, and Clean without overcomplicating it.
ASP.NET Core route constraints: A quick guide for developers
A quick ASP.NET Core routing guide that makes route constraints feel easier to use correctly.
Why Choose C# and .NET as My Programming Language?
A broader case for choosing C# and .NET, useful if you’re onboarding teammates or just defending the platform.
Building Your Own Mediator Pattern in Modern .NET
A custom mediator implementation with pipeline and notifications, plus a look at where the overhead shows up.
C# 14 Null-conditional Assignment: Complete Guide to Elegant Null Handling
C# 14 null-conditional assignment explained well enough to see why it removes a lot of boilerplate.
How to Build a High-Performance Cache Without External Libraries
A from-scratch cache design that moves from ConcurrentDictionary to keyed locking and better concurrency.
C# 14’s Null-Safe Member Assignment — Stop Writing Null Checks
Another C# 14 null-safe assignment piece, reinforcing how much cleaner member initialization can get.
Stop using Exceptions to control flow in .NET. It’s time to embrace the “Result” pattern.
A Result-pattern argument that pushes back on exception-driven control flow for expected outcomes.