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Learn AWS DynamoDB with C# and .NET: setup, CRUD, the Object Persistence Model, queries, and serverless Lambda best practices. Start building today. If you are building serverless .NET applications on AWS, sooner or later you will need a database that scales as effortlessly as AWS Lambda does. That database is almost always Amazon DynamoDB . In this DynamoDB C# tutorial, you will learn how to connect a .NET application to DynamoDB using the AWS SDK for .NET, perform CRUD operations with both the low-level and high-level APIs, run efficient queries, and avoid the pitfalls that catch most developers on their first serverless project. DynamoDB is a fully managed NoSQL key-value and document database. There are no servers to patch, no connection pools to tune, and it delivers single-digit millisecond latency at any scale. For Lambda functions written in C#, it is the natural fit: both services are pay-per-use, both scale horizontally, and neither requires you to manage infrastructur...

Learn C# extension methods with real-world examples. Write cleaner, reusable code, avoid common pitfalls, and follow best practices. Start coding today. If you have ever written string.IsNullOrWhiteSpace(name) and wished you could just write name.IsBlank() , you already understand the appeal of C# extension methods . Extension methods let you "add" new methods to existing types — including types you don't own, like string , DateTime , or IEnumerable<T> — without modifying their source code or creating a derived class. They are the reason LINQ reads so naturally, and they are one of the most practical tools for writing cleaner, more expressive C# code. In this tutorial you will learn how extension methods work under the hood, how to create your own, real-world examples you can drop into a production project today, and the best practices (and pitfalls) that separate helpful extension methods from confusing ones. What Are C# Extension Methods? An extension ...

Learn ASP.NET Core output caching with practical C# examples. Cache API responses, set policies, vary by query, and evict cache tags. Start speeding up your API today. If your API is doing the same database query hundreds of times a minute to return the same JSON, you're wasting CPU, wasting money, and making users wait. ASP.NET Core output caching fixes this with a single attribute or one line of middleware configuration: the server stores the fully rendered response and hands it back on the next request without touching your controller, your services, or your database. In this tutorial you'll learn how output caching works in ASP.NET Core 7, 8, 9 and 10, how it differs from response caching, how to configure cache policies, how to vary the cache by query string or header, how to invalidate cached entries with tags, and how to back the cache with Redis for multi-server deployments. Every example is runnable C#. What Is ASP.NET Core Output Caching? Output caching is serve...

Learn ASP.NET Core security best practices for 2026: stop XSS, CSRF, SQL injection & more with real C# code. Secure your web app today. Web applications are attacked constantly, and ASP.NET Core security is something every .NET developer needs to get right before shipping to production. The good news: ASP.NET Core ships with strong defaults for authentication, authorization, data protection, and request validation. The bad news: those defaults only help if you understand them, keep them switched on, and don't accidentally undo them with a well-meaning configuration change. This guide walks through the ASP.NET Core security best practices that matter most in 2026, with runnable C# examples and an explanation of why each one matters. We'll cover the OWASP Top 10 threats as they apply to .NET, from SQL injection and cross-site scripting (XSS) to broken authentication and misconfigured security headers, and finish with a checklist you can run against your own project. W...

Master LINQ in C# with 10 practical, runnable examples covering Where, Select, GroupBy, Join, and more. Learn best practices and common pitfalls today. If you write C# for a living, you use LINQ every single day — whether you realize it or not. This C# LINQ tutorial walks through 10 practical, runnable examples that cover the operations developers actually use in production: filtering, projecting, grouping, joining, aggregating, and paging data. Along the way, we explain why each operator behaves the way it does, so you can avoid the pitfalls (deferred execution, multiple enumeration, N+1 queries) that trip up even experienced .NET developers. All examples target .NET 8 or later and run as-is in a console app. Let's start with the sample data used throughout. Sample Data for This C# LINQ Tutorial We'll use a small product catalog with orders. Copy this into a Program.cs to follow along. using System; using System.Collections.Generic; using System.Linq; public rec...

Learn Azure OpenAI with C# step by step: set up GPT-4o in .NET, stream responses, use function calling and follow best practices. Start building today. If you have been searching for a practical Azure OpenAI C# tutorial, this guide walks you through integrating GPT-4o into a .NET application from scratch. You will learn how to authenticate against your Azure OpenAI resource, send chat completions, stream responses token by token, use function calling, and apply the best practices that separate a demo from a production-grade integration. Every example uses the official Azure.AI.OpenAI SDK and targets .NET 8 or later, so the code runs as-is. Why Use Azure OpenAI with C# Instead of the Public OpenAI API? Both services expose the same GPT-4o model, so why pick Azure? For most enterprise .NET teams, the answer comes down to three things: Data residency and compliance. Your prompts and completions stay inside your Azure subscription and region. Microsoft does not use your data to...