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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 14/12/2025

What’s next for the .NET Pulse Newsletter? You may have noticed it has been a while since the last .NET Pulse issue. Over the past year, a lot has changed for me: I stepped into a Tech Lead role and had a very active sports season, completing three triathlons and a trail run.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 18/11/2025

C# 14 introduces user-defined compound assignment operators. In previous versions, you could not overload the += operator. C# 14 allows user types to customize the behavior of compound assignment operators in a way that the target of the assignment is modified in-place.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 16/10/2025

C# 14 in the preview introduces the field keyword. It lets you write a property accessor body without declaring an explicit backing field. The compiler will replace the field keyword with a backing field. What do you think about this improvement?

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 15/10/2025

C# 14 in the preview introduces partial constructors and events. They must include exactly one defining declaration and one implementing declaration. The implementation declaration of a partial event must include add and remove accessors.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 14/10/2025

C# 14 in the preview allows an unbound generic type as an argument to nameof. For example, nameof(List<>) returns List. Previously, you could pass only closed generic types, such as List<int>, to return List.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 13/10/2025

C# 14 in the preview allows the null conditional member access operator on the left-hand side of an assignment. Previously, you had to check if the customer was null before assigning the order. In C# 14, the GetCurrentOrder method is not called if the customer is null.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 12/10/2025

C# 14 in the preview introduces extension members There is a new extension keyword that lets you define extension blocks for extension properties, methods, and operators This means you can group related extension members, enhancing code readability and maintainability Do you like the new feature?

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 11/07/2025

🎉 I'm incredibly honored to receive the Microsoft Most Valuable Professional award for the 4th time in the Developer Technologies category! I’m looking forward to another exciting year in the MVP program, continuing to learn, share, and grow with this amazing community.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 08/05/2025

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 06/05/2025

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 30/04/2025

Since .NET 5, ASP NET Core has built-in support for the Swashbuckle project (Swagger). ASP NET Core 9 removes Swashbuckle from the template. However, the .NET team added support for OpenAPI document generation. The AddOpenApi method registers the required dependencies.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 23/04/2025

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 18/04/2025

#1 How to Avoid Common EF Core Performance Pitfalls Entity Framework Core is one of the most popular ORMs in the .NET ecosystem, for good reason. It abstracts away the complexity of working with databases, allowing developers to focus on business logic rather than SQL queries.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 13/04/2025

System.Text.Json 9 introduces respecting required constructor parameters. You can control the behavior with the new RespectRequiredConstructorParameters JSON serialization option. If it's true, the serializer throws the JsonException for missing required properties.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 10/04/2025

When should you implement API versioning? The short answer is that as soon as your API is consumed by more than just yourself. This Friday, I'll show you how to manage API Versioning Like A Pro in ASP NET Core. Don’t miss out! Subscribe now! The link is in the comments.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 09/04/2025

“Fan out” refers to distributing or spreading functionality or data flow from a single point to multiple points. In messaging systems, it means to send one message to many recipients. Check my post to learn how easily to fan out HTTP requests in .NET. Link in the comments.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 08/04/2025

.NET 9 introduces the new LINQ method CountBy. It allows for calculating the frequency of a key. This improvement looks nice. What do you think?

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 07/04/2025

.NET 9 introduces a new GUID implementation based on timestamp and random. It makes GUID sequential, which makes it more suitable for relationship databases. Also, GUID gets the Version property to check the version of the created GUID.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 05/04/2025

How do you check if a list is not null and has elements? There are several ways to do it: 1. Classic way 2. List.Count way 3. Enumerable.Any way 4. Pattern matching way Which one do you prefer — or do you use a different approach? Let me know in the comments! 👇

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 02/04/2025

How to control the delay in the Task.Delay method in tests? You can pass the TimeProvider to the Task.Delay method since .NET 8. The TimeProvider will interpret the delay. You can use FakeTimeProvider to control the delay in tests.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 01/04/2025

C# Tip 💡 Use string.Join method to concatenate elements of a collection into a single string, inserting a specified separator between each element. ✔ More readable — No loops ✔ Better performance — Avoids unnecessary string allocations ✔ Less error-prone — No need to trim the last separator

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 31/03/2025

The OrderedDictionary type has existed in .NET since an early age. .NET 9 introduces the generic counterpart. It creates a dictionary where the order of key-value pairs can be maintained. Have you ever used OrderedDictionary?

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 27/03/2025

1. This Friday, .NET Pulse is diving into something we’ve all been waiting for — the Azure Service Bus Emulator! For years, testing Azure Service Bus locally meant relying on cloud instances, costly workarounds, or incomplete mocks. But not anymore!

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 26/03/2025

I like Refit. Refit is a .NET library designed to make interacting with RESTful APIs easy and efficient. With features like type safety, easy setup, and extensibility, Refit can save you time and reduce boilerplate code in your projects. Check out my post on how to start with Refit.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 25/03/2025

ASP NET Core 9 allows the disabling of HTTP metrics and the non-recording of values for specific endpoints and requests. For instance, automated systems check the Health endpoint, so recording metrics for it is not particularly helpful.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 07/03/2025

System.Text.Json serializer uses reflections for serialization and deserialization. Reflection is slow. .NET 5, alongside C# 9, introduces source generators. It allows the generation of code during compilation.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 05/03/2025

Pattern matching is handy in C#. The Type pattern tests the variable to see if it matches a given type. The Declaration pattern checks if the variable matches the type and assigns the result to a declared variable. Do you use these patterns?

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 04/03/2025

My favorite C# 12 feature: collection expressions! 🚀 A terse way to initialize collections, working with arrays, Span<T>, and more. The .. spread operator lets you inline collections easily. Do you like it?

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 03/03/2025

.NET 10 Preview 1 is now available! 🤓 Follow me if you want to be updated with new .NET 10 features. If you want more detailed .NET 10 features, consider subscribing to my newsletter! Link in the comments.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 02/03/2025

.NET 9 introduces CreateUnboundedPrioritized in System.Threading.Channels! Unlike FIFO channels, it dequeues the most prioritized element using Comparer<T>.Default or a custom IComparer<T> first. Do you use channels? For what use cases?

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 01/03/2025

A disrespectful attack on President Zelenskyy by the US President and Vice President. Ukraine must sign the second Budapest Memorandum without any security guarantees this time because Trump promised to finish the war, but doesn't have an idea how Victim blaming. putin is happy

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 01/03/2025

.NET8 introduces the new methods in the Random class. The GetItems method creates an array populated with randomly chosen items from the provided choices. The Shuffle method performs an in-place shuffle of an array or span. Have you used these methods yet?

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Reposted by Oleg Kyrylchuk 🇺🇦

Jakob Busk Sørensen @builditbusk.bsky.social · 20/02/2025

Definitely my favorite .NET newsletter 👍

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 27/02/2025

🎉 To celebrate the 50th edition of .NET Pulse, I’m sharing a special issue: "How to Become a Microsoft MVP: My Path and Tips for You." Stay tuned this Friday! 🚀 Subscription link in the comments ⬇️

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 25/02/2025

Entity Framework generates single queries using JOINs for related entities. JOINs can create significant performance issues in some scenarios. EF can split a single query into a few to eliminate such performance issues. Learn how to split queries. The link to my post is below

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 24/02/2025

System.Text.Json 9 introduces a new JsonStringEnumMemberName attribute. It allows customizing enum member names.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 23/02/2025

🔥 20% OFF Until February 🔥 A few weeks ago, I launched the sponsorship of the .NET Pulse newsletter. You can promote your service/product to 2,820+ confirmed subscribers. There is a special offer until February. Book your slots in March. Details are below⬇️

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 20/02/2025

Tired of messy constructors with too many parameters? The Builder Pattern in C# helps construct complex objects step by step, making your code more readable and maintainable. Learn how to implement it in this Friday’s .NET Pulse! Link for subscription in the comments ⬇️

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 19/02/2025

Why Are Delegates Important in C#? Delegates empower your C# code with flexibility, enabling type-safe method references, callbacks, and event-driven programming. They make your code more modular, reusable, and expressive — whether you're working with events, LINQ, or designing extensible APIs.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 18/02/2025

C# 13 introduces params collections. Previously, it was limited only to array types. You can now use params with any collection type, including Span<T> and ReadOnlySpan<T>. The compiler automatically allocates storage for the arguments when an interface type is used.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 15/02/2025

.NET Tip💡 Use structured logging in .NET to make your logs more searchable, filterable, and analyzable. Structured logs store data as key-value pairs instead of plain text messages, making it easy to query logs. Avoid string interpolation for logging for performance reasons. 👇

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 14/02/2025

C# Tip 💡 The nameof expression in C# is useful for obtaining the name of variables, properties, methods, and classes as a string at compile time. It helps avoid hardcoded string literals, improving maintainability and refactoring safety

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 13/02/2025

This Friday's issue is about Background Services in .NET! Learn how to run long-running tasks and process jobs in the background efficiently. 🔹 What are background services? 🔹 How to implement them in .NET? 🔹 Common use cases & best practices Make sure you're subscribed so you don’t miss it!

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 12/02/2025

For read-only scenarios, you should use the AsNoTracking behavior in EF Core. You can set it to: 1. Query 2. Context 3. All queries Such queries will be faster because EF doesn't set up information for tracking Use the AsTracking method for queries you want to track in the third case.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 11/02/2025

Health checks are essential for keeping your applications reliable and resilient. They help you: ✅ Detect failures before they impact users ✅ Enable automated monitoring and alerting ✅ Improve system observability and troubleshooting

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 10/02/2025

.NET 9 introduces the new LINQ method Index. It returns the implicit index of an enumerable. Would you use it?

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 06/02/2025

🚀 Coming This Friday: How to Standardize Code Formatting in .NET with .editorconfig. Are you struggling with inconsistent code styles across your team? This Friday, the .NET Pulse newsletter dives into the .editorconfig file. Don't miss it, and subscribe. The link is below.

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 01/02/2025

C# Tip ✅ Always include the original exception when re-throwing to preserve the stack trace. If you just need to re-throw, use throw; without ex;

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 30/01/2025

Are you tired of switching between Postman and your IDE to test APIs? This Friday in .NET Pulse, we’re exploring .http files, an easy way to send API requests directly from VS Code, Visual Studio, and Rider. Join over 2,710 engineers reading .NET Pulse. Link below ⬇️

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Oleg Kyrylchuk 🇺🇦 @okyrylchuk.dev · 23/01/2025

Coming this Friday: The latest .NET Pulse newsletter! This week, we’re talking about the Decorator Pattern: 🎨 What it is ⚙️ How to implement it in .NET 📦 Use cases Make your code cleaner and more flexible! 💻 Join over 2,700 subscribers! Subscribe: go.okyrylchuk.dev/vbokBk

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