C# Advent Calendar 2025

Welcome to the 2025 C# Advent! Make sure to follow @csadvent on X. Got questions? Ask @mgroves on X or Matt Groves on LinkedIn.

All spots are currently claimed! However, you can sign-up as a substitute! Get more details here.

December 1

Part 1

Claimed by: Christopher C. Johnson

From Encrypted Messaging to Secure AI: Cryptography Patterns in .NET 10

Part 2

Claimed by: Cameron Presley

Reducing Bugs by Using the Model View Update Pattern

December 2

Part 1

Claimed by: Roman Stoffel

Create Types on Demand and Cecilifier

Part 2

Claimed by: Gérald Barré

Creating a custom MSBuild SDK to reduce boilerplate in .NET projects

December 3

Part 1

Claimed by: Thomas Ardal

Fetching GitHub content from C#

Part 2

Claimed by: Lee Englestone

Santa's Workshop with AI Elf Agents

December 4

Part 1

Claimed by: Stephen Cleary

Debug Dumps in Visual Studio

Part 2

Claimed by: Ardalis

Single File Test Suites in .NET C#

December 5

Part 1

Claimed by: Victor Frye

Gifting SDKs with Kiota

Part 2

Claimed by: Mykyta Kovalenko

.NET Performance: Efficient Async Code

December 6

Part 1

Claimed by: Sarah Dutkiewicz

St. Nicholas' Goodies - A TUI!

Part 2

Claimed by: Jochen Kirstätter

December 7

Part 1

Claimed by: Dave Brock

Parsing Santa's workshop with strongly typed data (without the coal)

Part 2

Claimed by: Chris Woody Woodruff

Debugging Entity Framework Core: 8 Real-World Query Anti‑Patterns (and How to Fix Them)

December 8

Part 1

Claimed by: Michael Eaton

A Christmas Trivia game using C# and Spectre.Console

Part 2

Claimed by: Al Nyveldt

Make Copilot Work Your Way: Building MCP Servers in C#

December 9

Part 1

Claimed by: Jonathan "J." Tower

Reusing Your Existing .NET REST APIs for AI with MCP

Part 2

Claimed by: Kevin Griffin

What's New in C# 14: Extension Members

December 10

Part 1

Claimed by: Luis Beltran

Meet Microsoft Agent Framework — Your .NET Agent Toolkit

Part 2

Claimed by: Jorge Levy

Create your MCP Server using Azure Functions

December 11

Part 1

Claimed by: 2code ^ !2code

2 code a Roslyn Source Generator - C# Advent Calendar 2025

Part 2

Claimed by: Poornima Nayar

Sending sweet treats with Google Pub/Sub

December 12

Part 1

Claimed by: Sam Basu

Modern .NET with Uno Platform & AI

Part 2

Claimed by: Chris Ayers

Getting Started with the Aspire CLI

December 13

Part 1

Claimed by: John Waters

Sending Holiday Cheer in .NET with Scriban and MailKit

Part 2

Claimed by: Barret Blake

C# Advent 2025 - Extension Members

December 14

Part 1

Claimed by: Matt Eland

16 Tips for Writing AI-Ready C# Code

Part 2

Claimed by: Conrad Akunga

Dynamically Changing Decimal & Thousand Separators At Runtime

December 15

Part 1

Claimed by: Rodrigo Juarez

Sentiment Analysis in C#: Azure AI Language or LLMs

Part 2

Claimed by: Vladan Petrovic

TUnit: The New Sheriff in Town for .NET Testing

December 16

Part 1

Claimed by: Andy Wilson

Manufacturing Certainty: Load Testing With Azure Load Testing

Part 2

Claimed by: Stefan Mitic

EF Core 10 Turns PostgreSQL into a Hybrid Relational-Document DB

December 17

Part 1

Claimed by: Alexey Fedorov

Your cache is not protected from cache stampede

Part 2

Claimed by: Matt Mattei

Building a Fibonacci Sphere with AI-Assisted Development

December 18

Part 1

Claimed by: Alexandre Nédélec

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Part 2

Claimed by: Davide Bellone

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December 19

Part 1

Claimed by: Ed Charbeneau

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Part 2

Claimed by: Sam Gomez

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December 20

Part 1

Claimed by: Jeffry Morris

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Part 2

Claimed by: Martin Zikmund

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December 21

Part 1

Claimed by: Simon Painter

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Part 2

Claimed by: Tim Purdum

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December 22

Part 1

Claimed by: Juan Miguel C. Nieto

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Part 2

Claimed by: Irina Dominte(Scurtu)

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December 23

Part 1

Claimed by: Aaron LaBeau

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Part 2

Claimed by: Kyle McMaster

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December 24

Part 1

Claimed by: Piotr Kolodziej

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Part 2

Claimed by: Santhosh Reddy Vootukuri

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December 25

Part 1

Claimed by: Moaid Hathot

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Part 2

Claimed by: Stefan Pölz

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