CSharp-Coder

Learn ASP.NET Core output caching with real C# examples. Speed up API responses dramatically with policies, cache invalidation & Redis. Start caching today! If your API is hitting the database on every single request for data that barely changes, you are burning CPU, database connections, and money for nothing. ASP.NET Core output caching is one of the highest-impact, lowest-effort performance wins available in modern .NET: with a few lines of code, you can serve repeat requests in microseconds instead of milliseconds — often cutting response times by 90% or more and slashing database load dramatically. Output caching was introduced in .NET 7 as a first-class middleware and has matured significantly through .NET 8 and .NET 9, gaining built-in Redis support, tag-based invalidation, and clean integration with Minimal APIs and MVC controllers. In this tutorial, you will learn how output caching works, how it differs from response caching (a distinction that confuses even senior d...

Learn Google Cloud Pub/Sub in C# with this .NET tutorial. Publish and subscribe to messages on GCP with runnable code examples. Start building today! If you're building distributed systems on Google Cloud Platform, Google Cloud Pub/Sub is the messaging backbone you'll reach for again and again. It's a fully managed, globally distributed publish/subscribe service that decouples the services that produce events from the services that process them — no brokers to patch, no clusters to scale, no partitions to rebalance. In this tutorial, you'll learn how to use Google Cloud Pub/Sub with C# and .NET: creating topics and subscriptions, publishing messages asynchronously, consuming them with the high-throughput streaming subscriber, and handling the real-world concerns — ordering, retries, dead-letter queues, and exactly-once processing — that separate a demo from a production system. What Is Google Cloud Pub/Sub and Why Use It? Pub/Sub implements the classic publish/s...

Learn CQRS and MediatR in ASP.NET Core with practical C# examples. Master commands, queries, and pipeline behaviors — start building cleaner APIs today. If you have ever opened a service class in an ASP.NET Core project and found a 2,000-line file that reads data, writes data, validates input, sends emails, and logs everything in between, you already understand why CQRS and MediatR in ASP.NET Core have become two of the most searched-for patterns in the .NET ecosystem. CQRS (Command Query Responsibility Segregation) splits your application into two clean halves — operations that change state and operations that read state — while MediatR gives you a lightweight, in-process messaging library to wire it all together without controllers knowing anything about your business logic. In this tutorial, you will learn what CQRS actually is (and what it is not), why MediatR is the most popular way to implement it in .NET, and how to build a complete, runnable example with commands, queries,...

Master C# generics with this complete tutorial. Learn generic classes, methods, constraints & real-world examples. Start writing type-safe C# code today! If you've ever used List<T> or Dictionary<TKey, TValue> , you've already used C# generics — but do you know how to build your own? In this C# generics tutorial, you'll learn how generics let you write reusable, type-safe code once and use it with any type, without sacrificing performance or compile-time safety. We'll cover generic classes, generic methods, constraints, and real-world use cases like repositories and result types that you'll actually use in production applications. Whether you're a beginner wondering what <T> means, or an intermediate developer looking for generics best practices, this guide walks through everything with runnable code examples. What Are Generics in C#? Generics, introduced in C# 2.0, allow you to define classes, methods, interfaces, and delegate...

Learn how to build a RAG chatbot in C# using Semantic Kernel. Step-by-step tutorial with embeddings, vector search & code. Start building today! Building a RAG chatbot in C# is one of the most in-demand AI skills for .NET developers in 2026 — and for good reason. Retrieval-Augmented Generation (RAG) lets you build an AI chatbot that answers questions using your own documents — internal wikis, PDFs, product manuals, support tickets — instead of relying on whatever the model memorized during training. In this tutorial, you'll build a complete RAG chatbot using C# and Microsoft's Semantic Kernel , the official .NET SDK for orchestrating large language models. We'll cover embeddings, vector search, chunking, prompt grounding, and the pitfalls that trip up most first-time builders. By the end, you'll have a working console chatbot that ingests documents, retrieves the most relevant passages for each question, and generates grounded, citation-friendly answers — al...