Preface

Microsoft has released a new open source and cross-platform web application framework, called ASP.NET Core. It runs on top of .NET Core, which is also open source, and is primarily used with the C# programming language. You are no longer tied to using Windows with ASP.NET, and you can now develop on a Mac and deploy to Linux. This new platform also offers much higher performance.

In today's world, a web application that only performs well on a developer's workstation and fails to deliver high-performance in production, is unacceptable. The way that web applications are now deployed at scale has changed, and development practices must adapt to take advantage of this. By reading this book, you'll learn about the modern way of making high-performance web applications, and how to do this with ASP.NET Core.

This book addresses web application performance-improvement techniques from both a general standpoint (HTTP, HTTPS, HTTP/2, TCP/IP, database access, compression, I/O, asset optimization, caching, message queuing, and other concerns) and from a C#, ASP.NET Core, and .NET Core perspective. This includes delving into the details of the latest frameworks and demonstrating software design patterns that improve performance.

We will highlight common performance pitfalls, which can often occur unnoticed on developer workstations, along with strategies to detect and resolve these issues early. By understanding and addressing challenges upfront, you can avoid nasty surprises when it comes to deployment time.

We will introduce performance improvements along with the trade-offs that they entail. We will strike a balance between premature optimization and inefficient code by taking a scientific and evidence-based approach, focusing on the big problems and avoiding changes that have little impact.

We assume that you understand the importance of performance for web applications, but we will recap why it's crucial. However, you may not have had any specific or actionable advice, or have much experience of performance problems occurring in the wild.

By reading this book, you'll understand what problems can occur when web applications are deployed at scale to distributed infrastructure, and know how to avoid or mitigate these issues. You will gain experience of how to write high-performance applications without having to learn about issues the hard way, possibly late at night.

You'll see what's new in ASP.NET Core, why it's been rebuilt from the ground up, and what this means for performance. You will understand the future of .NET Core and how you can now develop on and deploy to Windows, Mac OS X, and Linux. You'll appreciate the performance of new features in ASP.NET Core, including updates to the Razor view engine, and you will be aware of cross platform tools, such as Visual Studio Code.