Ivan Kahl's Blog

Beyond CRUD: A Practical Guide to Modeling Business Processes in REST APIs

Stop forcing complex business logic into basic CRUD operations. This guide covers 5 actionable patterns for designing RESTful APIs that communicate true intent. Learn when to nest sub-resources, how to model complex actions, and why leaning into RPC-style verbs can be an acceptable compromise.

.NET

8 NDepend Rules to Enforce Domain-Driven Design in .NET

Learn how to use NDepend and CQLinq to automate Domain-Driven Design (DDD) enforcement in .NET. This guide provides eight practical rules to protect architectural boundaries, ensure entity encapsulation, and maintain aggregate root consistency to prevent your codebase from degrading.

C#

Decompiling the New C# 14 field Keyword

C# 14’s field keyword helps reduce property boilerplate code. This article examines the IL code behind the new keyword and highlights caveats you must know before refactoring your codebase.

Guides

Mastering the C# Dispose Pattern

Mastering C# IDisposable is crucial for reliable resource management. Learn how to deterministically clean up unmanaged resources like database connections, file handles, and network sockets, and avoid memory leaks.

Stop Spaghetti SQL: Simplify Complex Queries with Postgres CTEs in Supabase

Modern web applications deal with massive amounts of complex data, and relational databases are a popular choice for keeping everything organized. But even with structured data, queries can turn into nightmares when you need to retrieve large amounts of interconnected information. Take a music streaming app that wants to retrieve

Guides

What's New in C# 14: Null-Conditional Assignments

C# 14, coming with .NET 10, introduces null-conditional assignment, a feature that lets you safely assign values to properties or indexers without endless if statements. Learn more about this new feature in this article.

.NET

What's New in C# 14: User-Defined Compound Assignments

C# 14, coming with .NET 10, introduces user-defined compound assignments. It allows for the creation of more efficient assignment operators, preventing unnecessary object creation. Discover how to implement and use this new feature, and learn about the potential pitfalls to watch out for.

Google Gemini Receipt Parser for YNAB

Tired of manually logging expenses in YNAB? Discover how I automated the importing and categorising of transactions in YNAB from receipt images using Google Gemini. You'll also see how easy it is to run the Docker container for your own budget.

Guides

Beyond the Random Class: Cryptographic Randomness in .NET 6+

Learn how to generate cryptographically secure random numbers in .NET applications using the RandomNumberGenerator class. Discover the importance of true randomness for security-sensitive tasks and explore best practices for generating unpredictable values.

C#

C# Null-Conditional (?.) & Null-Coalescing (??) Operators Explained

Learn how C#'s null-conditional and null-coalescing operators can help you write cleaner, more robust code by gracefully handling null values.

Guides

Introduction to Mapster in C#: Benefits and Quick Start Guide

Mapster is a versatile, high-performance object mapping library for .NET. This blog post provides an introductory guide to using Mapster, highlighting its key features and benefits for efficient data mapping in C# applications.

C#

Extension Methods in C#

Have you ever needed to extend a class provided by a third-party library? Perhaps you want to add additional functionality or simplify a particular set of methods in the library.

Powershell

Case-sensitive and Case-insensitive String Comparisons in PowerShell

Discover how to perform case-sensitive and case-insensitive string comparisons in PowerShell. This article explains using operators like -eq, -ceq, -like, and -clike for precise string handling.

.NET

Logging .NET to AWS CloudWatch: Using NLog

Learn how to log .NET applications to AWS CloudWatch using NLog in this comprehensive guide. It covers setting up NLog, configuring it to log to CloudWatch, and customizing settings for optimal performance.

.NET

Logging .NET to AWS CloudWatch: Using Serilog

Learn how to log .NET applications to AWS CloudWatch using Serilog in this detailed guide. It covers setting up Serilog, integrating it with CloudWatch, and customizing log settings for optimal performance.

.NET

Logging .NET to AWS CloudWatch: Understanding the basics using AWS SDK

Learn to log .NET applications to AWS CloudWatch using the AWS SDK in this step-by-step guide. It covers setting up the SDK, creating log groups and streams, and sending log messages programmatically.

Dependency Injection

Introduction to Aspect-Oriented Programming (AOP) in .NET with Autofac Interceptors

Explore Aspect-Oriented Programming (AOP) in .NET using Autofac Interceptors with this guide. It demonstrates setting up Autofac, creating interceptors, and applying AOP principles to improve code modularity and readability.

.NET Core

Three Methods to Convert Strings into Enums in C#

I recently had to solve the problem of converting strings into enums in C#. There are a few different solutions you can implement depending on your requirements. This article aims to show you some of these solutions and when to use each one.

.NET

Using Config.Net for .NET Application Configurations

A while back I wrote an article detailing how to create custom configuration sections in the App.config file in .NET. This is by far the most...

C#

The Comprehensive Guide to Custom DateTime String Formats in C#

When working with C#, we can convert a DateTime object to a string. If we don't specify any formatting options, the default DateTime string format will be outputted. However, C# gives us the power to completely customise how the DateTime object should be outputted using custom format specifiers.

SQL Server

Backing Up and Restoring Native SQL Server Backups in AWS RDS

We've recently been moving all our infrastructure over to AWS at Mercury. This has come with many benefits such as finer control over security and easier maintenance of our infrastructure

AWS

Getting AWS Lambda Environment Variables in all supported languages

Accessing these environment variables is different in every programming language supported by AWS Lambda as each language uses a native API for retrieving the environment variables instead of introducing a dependency for retrieving environment variables

Slack

Send Slack messages from anywhere using Webhook Integration

I started working at a new company called Mercury FX International. We specialize in foreign exchange and I help maintain and innovate the software that we use. This can range from menial tasks such as fixing minor bugs to major projects like...

Windows

Enabling and Disabling Hyper-V in Powershell

I sometimes find myself having to disable Hyper-V in Windows 10 temporarily in order to run some other virtualization software like VirtualBox. While it is possible to enable and disable Hyper-V in Window Features, I find it a lot more convenient running a Powershell command to enable and disable it.

Sage CRM

Using SData 2.0 in Sage CRM: Part 5 - A word on authentication

In this last post in this series on using SData 2.0 in Sage CRM, I just want to leave some comments on authenticating with SData 2.0. If you