🎄 It’s that magical time of year again! 🎅🏻
Christmas is twinkling on the horizon, and that means one thing — it’s time for the 12th annual F# Advent in English!

It’s incredible to think that our tradition began all the way back in 2014. For over a decade, the F# community has gathered during Advent to share stories, ideas, code experiments, and a shared love for this beautiful language. 💜

This year, we’re keeping the festive momentum going — with 24 main slots leading up to Christmas Eve, plus a few bonus entries to make room for all the amazing contributors who want to join in.

So grab a cup of cocoa ☕, fire up your favorite editor, and let’s make this 2025 F# Advent one to remember — filled with insight, creativity, and community cheer. 🌟

Rules

1. Choose F# a related topic for your blog post and reserve the slot on BlueSky, Mastodon, X or leave a comment on this post. Please note that you do not have to announce the topic until the date (but you can).
2. Prepare a blog post or video in English.
3. Publish your post on a specified date (according to the calendar).
4. Post the link to your post on BlueSky, Mastodon or X  with hashtags #fsharp and #FsAdvent.

ID	Date	Author	Post Title
#2501	Dec 01 (Mon)	‪Vladimir Shchur	The Oxpecker 2
#2502	Dec 02 (Tue)	Steve Goguen	Domain Modeling Made Denumerable
#2503	Dec 03 (Wed)	Houston Haynes	Building ‘Ask AI’
#2504	Dec 04 (Thu)	Sam Smucny	Language Server Protocol in F#
	Dec 04 (Thu)	Nick	Parallelising Heterogeneous Async Calls
#2505	Dec 05 (Fri)	Jo Van Eyck	fsi-mcp: injecting AI coding agents into my F# REPL workflow
#2506	Dec 06 (Sat)	Jozsef Uri	Implementing my own bookmark manager
#2507	Dec 07 (Sun)	SoweliP	Interactive development in F#
#2508	Dec 08 (Mon)	Ben Copeland	F# in Production: What I Know After Four Years
#2509	Dec 09 (Tue)	Millennium	Comprehensive Guide to SRTP Gymnastics
#2510	Dec 10 (Wed)	Urs Enzler	I like my F# code type annotation-free
#2511	Dec 11 (Thu)	Mathias Brandewinder	Adding Goal Seek to Quipu (and helping Santa with it!)
#2512	Dec 12 (Fri)	John Azariah	Tagless Final in F# (series of 6 posts)
#2513	Dec 13 (Sat)	Ronald Schlenker	Making of A Programming Language
#2514	Dec 14 (Sun)	halcwb	Taming the Brown Field with F#: Interactive Refactoring for Mature Codebases
#2515	Dec 15 (Mon)	jkone27	F# and PowerShell >🎄?
#2516	Dec 16 (Tue)	Angel Munoz	Exploring MonoGame with F#
#2517	Dec 17 (Wed)	Owais	Parsing and Lexing in F#
#2518	Dec 18 (Thu)	Kevin	F#, Microsoft Agent Framework, MCP and Bitcoin
#2519	Dec 19 (Fri)	Scott Wlaschin	Designing weaving software
	Dec 19 (Fri)	Tuomas Hietanen	A Brief Introduction to Quantum Computing for F# Developers
#2520	Dec 20 (Sat)	romain-deneau	“Safe Clean Architecture” book.
#2521	Dec 21 (Sun)	Dag Brattli	Introduction to Fable.Python
#2522	Dec 22 (Mon)	Jordan Marr	Create a Cloudflare Worker in .NET?!
#2523	Dec 23 (Tue)	P. León	Complying with the Law with F# and Event Sourcing
	Dec 23 (Tue)	Adam Granicz	Introducing WebSharper source code generators
#2524	Dec 24 (Wed)	Paweł Stadnicki	What F# Knows About Functors and What Comes Next

Advent of Code

Two years ago, we decided to spice up the Advent season by creating a private board for those participating in Advent of Code (AoC) and coding in F#. If you’re planning to dive into AoC this December, we’d love for you to join us. Let’s make this holiday season one to remember!

History of F# Advent

F# Advent Calendar is a long tradition in the F# community

• F# Advent Calendar in English: 2024, 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016, 2015, 2014
• F# Advent Calendar (in Japanese):  2024, 2023, 2022, 2021, 2020, 2019, 2017, 2016, 2015, 2014, 2013, 2012, 2011, 2010

That inspired the C# Advent Calendar, Q# Advent Calendar, and many others.

Can you believe it’s that time of year again? 🎅🏻 Christmas is just around the corner, and we’re gearing up for the 11th annual F# Advent in English! It’s hard to believe that our journey started back in 2014. Each year since, we’ve come together during the Advent season to share our F# stories, experiences, and unbridled passion.

This year will be no different, although we’re switching things up a bit. We’re starting with a main schedule that includes 24 slots, and we’ll be adding extra slots to make sure there’s room for everyone who wants to participate.

Join F# Advent Calendar today!

Rules

1. Choose F# a related topic for your blog post and reserve the slot on BlueSky, Mastodon, X or leave a comment on this post. Please note that you do not have to announce the topic until the date (but you can).
2. Prepare a blog post or video in English.
3. Publish your post on a specified date (according to the calendar).
4. Post the link to your post on Twitter or Mastodon with hashtags #fsharp and #FsAdvent.

ID	Date	Author	Post Title
#2401	Dec 01 (Sun)	SchlenkR	PXL-Jam Christmas 2024
#2402	Dec 02 (Mon)	Vladimir Shchur	How to write Fable compiler plugin
#2403	Dec 03 (Tue)	RAPHAËL	FSharp fsx scripts as a project’s viable starting point
#2404	Dec 04 (Wed)	Steve Goguen	The Gödelian Toolkit: Systematically Testing Simple Languages
#2405	Dec 05 (Thu)	Kevin	My Journey towards Functional Programming and F#
#2406	Dec 06 (Fri)	jkone27	Feliz Navidad 🎄
#2407	Dec 07 (Sat)	Tim Knauf	A Game in F#? Why, yes indeed.
#2408	Dec 08 (Sun)	Michael Winch	Minimising cognitive load in F#
#2409	Dec 09 (Mon)	TRISTIAN	A poor mans F# dependency injection for AWS Lambda
#2410	Dec 10 (Tue)	Andrew	Intro to FS.FluentUI
#2411	Dec 11 (Wed)	kaeedo	Protect your ASP.NET site using FIDO2 Passkeys
#2412	Dec 12 (Thu)	Dexter	Functional String Processing: Extend with F#, Call from C#
#2413	Dec 13 (Fri)	Urs Enzler	Your First day on the team = releasing Your first feature
#2414	Dec 14 (Sat)	Paul Blasucci	FaultReport: an Theoretical Alternative to Result
#2415	Dec 15 (Sun)	Edgar Gonzalez	Fabulous.AST
#2416	Dec 16 (Mon)	Ian Russell	Celebrating 5 Years In Production
#2417	Dec 17 (Tue)	Bentok	F# Discriminated Unions with SQL Enumerations
#2418	Dec 18 (Wed)	József Uri	Football with F# – Part 1
#2419	Dec 19 (Thu)	Matthew Watt	Why the F# would I write real code like this?
#2420	Dec 20 (Fri)	Damian Płaza	Functions (and facts) describe the world
#2421	Dec 21 (Sat)	Souvanxay Luangsouvannavong	Building mobile apps with F# and WebSharper
#2422	Dec 22 (Sun)	Adam Granicz	IntelliLogo
#2423	Dec 23 (Mon)	Eriawan still WFH	What’s new in F# in .NET 9.0 and .NET 9.0 SDK dotnet restore audit impact
#2424	Dec 24 (Tue)	Paweł Stadnicki	Data Apps in F# or F# in Data Apps?

Advent of Code

Two years ago, we decided to spice up the Advent season by creating a private board for those participating in Advent of Code (AoC) and coding in F#. If you’re planning to dive into AoC this December, we’d love for you to join us. Let’s make this holiday season one to remember!

Reminder for every who solves adventofcode.com in #fsharp It also starts tomorrow, and we have a private board with F# folks 393584-7799c026. You are welcome to join!

— Sergey Tihon 🦔🦀 (@sergeytihon.com) 2024-11-30T13:10:18.003Z

History of F# Advent

F# Advent Calendar is a long tradition in the F# community

• F# Advent Calendar in English: 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016, 2015, 2014
• F# Advent Calendar (in Japanese):  2024, 2023, 2022, 2021, 2020, 2019, 2017, 2016, 2015, 2014, 2013, 2012, 2011, 2010

That inspired the C# Advent Calendar, Q# Advent Calendar, and many others.

Christmas is approaching again 🎅🏻. It’s almost unbelievable that we’re celebrating the 10th annual F# Advent in English! Our journey began back in 2014, and since then, every year has seen us come together during the Advent season to share our F# stories, experiences, and unbridled passion.

This year is not an exception, but we will do it slightly differently. We kick things off with a main schedule featuring 32 slots, and we’ll be adding extra slots to accommodate all our eager participants.

Join F# Advent Calendar today!

Rules

1. Choose F# a related topic for your blog post and reserve the slot on Twitter, Mastodon or leave a comment on this post. Please note that you do not have to announce the topic until the date (but you can).
2. Prepare a blog post or video in English.
3. Publish your post on a specified date (according to the calendar).
4. Post the link to your post on Twitter or Mastodon with hashtags #fsharp and #FsAdvent.

ID	Date	Author	Post Title
#2301	Dec 01 (Fri)	Paweł Stadnicki	Flying with F#
#2302	Dec 02 (Sat)	Lars Furu Kjelsaas	Testing a derived state
extra	Dec 02 (Sat)	Compositional IT	Announcing SAFE Template v5
#2303	Dec 03 (Sun)	Hamilton Greene	Build a Simple Markdown Blog with F# / Giraffe
#2304	Dec 04 (Mon)	Urs Enzler	Our Experience with Bi-temporal Event Sourcing
#2305	Dec 05 (Tue)	Viktor Schepik	Building a React F# UI for an Embedded System
#2306	Dec 06 (Wed)	Bentok	Choosing Elegance: The Case for F# in Application Development
#2307	Dec 07 (Thu)	Gergő Gyalus	Showcasing Feliz.Engine with WebSharper.React
#2308	Dec 08 (Fri)	Teerawat Wuttiwat	From Scrape To API
#2309	Dec 09 (Sat)	Vladimir Shchur	The best language for serverless applications in 2024
#2310	Dec 10 (Sun)	Toni Lucca	A little F# event-sourcing library. Part II.
extra	Dec 10 (Sun)	Andrew Sutton	FS.FluentUI- A New F# UI Library
#2311	Dec 11 (Mon)	József Uri	Proxying with WebSharper
#2312	Dec 12 (Tue)	johnazariah	Y, oh Y!
#2313	Dec 13 (Wed)	Kim S	no reply 🤐
#2314	Dec 14 (Thu)	Marcin Golenia	HATEOAS in F#
#2315	Dec 15 (Fri)	Damian Płaza	FSM – Functional State Machines
#2316	Dec 16 (Sat)	Angel Munoz	Revisiting WASM for F#
#2317	Dec 17 (Sun)	Raymen Scholten	Possibilities of abstractions
extra	Dec 17 (Sun)	Kunjan Dalal	F# 8: Unwrapping New Features and Nostalgic Connections
#2318	Dec 18 (Mon)	Flavioc	Exploring exoplanets with Type Providers and Plotly: Part1, Part2, Part3
#2319	Dec 19 (Tue)	Edgar Gonzalez	Provoking the Muse: An Incitement to Action
#2320	Dec 20 (Wed)	let bmitc = me	delayed
#2321	Dec 21 (Thu)	yves	WebSharper CRUD patterns
#2322	Dec 22 (Fri)	Scott Arbeit	A random walk in the direction of functional enlightenment
#2323	Dec 23 (Sat)	sudipta mukherjee	Data Journalism with F# and Squirrel.
#2324	Dec 24 (Sun)	Eriawan still WFH	Evolving improvement on existing features in the latest F# release in 2023: F# 8.0 (and a surprise)
#2325	Dec 25 (Mon)	dawe	H-ing gracefully
#2326	Dec 26 (Tue)	Matt Eland	Exploratory Data Analysis with F#, Plotly.NET, and ML.NET DataFrames
#2327	Dec 27 (Wed)	SchlenkR	GOOD NEWS – for .Net, C#, F#, and the Web
#2328	Dec 28 (Thu)	Djordje Djukic	delayed
extra	Dec 28 (Thu)	@fslaborg	State of FsLab 2023
#2329	Dec 29 (Fri)	jkone27	DI for F# butterflies 🦋
#2330	Dec 30 (Sat)	Orlando Anderegg	Down the Concurrency Rabbit Hole
#2331	Dec 31 (Sun)	kaeedo	HTMX, WebSockets, SignalR and you
#2332	Jan 01 (Mon)	Adam Granicz	A new fullstack SPA template for WebSharper and what’s next

Advent of Code

In the preceding year, we decided to inject some extra enjoyment into the Advent season by establishing a private board for participants of Advent of Code (AoC) who code in F#. If you’re gearing up for AoC this December, we invite you to come and join us. Let’s make this holiday season even more memorable!

History of F# Advent

F# Advent Calendar is a long tradition in the F# community

• F# Advent Calendar in English: 2022, 2021, 2020, 2019, 2018, 2017, 2016, 2015, 2014
• F# Advent Calendar (in Japanese): 2022, 2021, 2020, 2019, 2017, 2016, 2015, 2014, 2013, 2012, 2011, 2010

That inspired the C# Advent Calendar, Q# Advent Calendar, and many others.

F# Advent Calendar is a long tradition in the F# community

• F# Advent Calendar in English: 2021, 2020, 2019, 2018, 2017, 2016, 2015, 2014
• F# Advent Calendar (in Japanese): 2022, 2021, 2020, 2019, 2017, 2016, 2015, 2014, 2013, 2012, 2011, 2010

That inspired the C# Advent Calendar, Q# Advent Calendar, and many others.

Christmas is approaching again, and now is the time to prepare our spirit for it with the goodness of F#. Please join, reserve one of 56 slots, and spread your thoughts and love to F# with the community.

Join F# Advent Calendar today!

Rules

1. Choose F# a related topic for your blog post and reserve the slot on Twitter, Mastodon or leave a comment on this post. Please note that you do not have to announce the topic until the date (but you can).
2. Prepare a blog post in English.
3. Publish your post on a specified date (according to the calendar).
4. Post the link to your post on Twitter or Mastodon with hashtags #fsharp and #FsAdvent.

Advent fun with F# and Advent of Code

ID	Date	Author	Post Title
#2201	Dec 01 (Thu)	Fast F#	Fast Iteration of Set Bits in BitSet
#2202	Dec 01 (Thu)	Mårten Rånge	Recreating ST-NICC 2000 1st place demo in F#
#2203	Dec 02 (Fri)	Urs Enzler	Our journey to F#: C#-F# Interop
#2204	Dec 02 (Fri)	@LOGAN	Implementing General Computation
#2205	Dec 03 (Sat)	Steve Goguen	Part 1. F# ↔ C# — What would it take? Part 2. Copying the Fable Compiler Part 3. F# → C#? Or Making Dart Code Look like C#?
#2206	Dec 03 (Sat)	Ben Copeland	Domain-Driven Microservices with F#
#2207	Dec 04 (Sun)	Mathias Brandewinder	Simulating the Wrapinator 5000
#2208	Dec 04 (Sun)	Denis Bobrov	Communicating with other languages and runtimes, aka FFI in F#
#2209	Dec 05 (Mon)	Nick Blair	Logging wide events with F#
#2210	Dec 05 (Mon)	Einar Norðfjörð	The Equinox Programming Model
#2211	Dec 06 (Tue)	Paweł Stadnicki	Geospatial is a function of your life
#2212	Dec 06 (Tue)	John Azariah	This is not a Monad Tutorial
#2213	Dec 07 (Wed)	Teerawat Wuttiwat	From Domain to Web with Safe Stack
#2214	Dec 07 (Wed)	Hamilton Greene	Build a simple F# web API with Giraffe
#2215	Dec 08 (Thu)	@bmitc_	Symbolic expressions in F#
#2216	Dec 08 (Thu)	Enes Poyraz	Creating a F# WebAPI with ChatGTP
#2217	Dec 09 (Fri)	@dawe	Tortilla Flow
#2218	Dec 09 (Fri)	Mark Pattison	Parsing a GPX file using FSharp.Data
#2219	Dec 10 (Sat)	@jannik	F# event sourcing with Marten
#2220	Dec 10 (Sat)	Michal Nebes	Generating chord progressions in F#
#2221	Dec 11 (Sun)	Edgar Gonzalez	See it, Say it, Sort it! An example of how to contribute to the F# compiler as a beginner
#2222	Dec 11 (Sun)	@Kim	From C# to F# in 30 days
#2223	Dec 12 (Mon)	Patrick Kelly	C#’s Generic Math from F#
#2224	Dec 12 (Mon)	Tom Banham	Aggregating Errors in F#
#2225	Dec 13 (Tue)	Jimmy Byrd	Cancellable Tasks And Beyond
#2226	Dec 13 (Tue)	@jkone27	F# Type Inference
#2227	Dec 14 (Wed)	Christophe Moinard	Music theory in F# – Introduction Music theory in F# – Random note Music theory in F# – Major scale Music theory in F# – Chords of the Major scale
#2228	Dec 14 (Wed)	Nick Corlett	Reader and Async and Result, oh my!
#2229	Dec 15 (Thu)	József Uri	Dart in F#, differently
#2230	Dec 15 (Thu)	Damian Płaza	Many faces of DDD Aggregates in F#
#2231	Dec 16 (Fri)	Angel Munoz	Mixing Google Cloud and F#
#2232	Dec 16 (Fri)	Atle Rudshaug	Interacting with devices using MQTT
#2233	Dec 17 (Sat)	Kunjan Dalal	Breath of Fresh Air with Solid JS and Fable.Solid
#2234	Dec 17 (Sat)	Fran González	Creating DSLs using F#’s Computation Expressions
#2235	Dec 18 (Sun)	Constantin Tews	A little story about Fli
#2236	Dec 18 (Sun)	Phillip Carter	Microsoft doesn’t hate F#
#2237	Dec 19 (Mon)	Ian Russell	Retrospective 2022
#2238	Dec 19 (Mon)	David Glassborow	A brief introduction to WebAssembly in .NET and F#
#2239	Dec 20 (Tue)	Bartosz Sypytkowski	Plumtree – epidemic broadcast trees
#2240	Dec 20 (Tue)	Stachu Korick	Darklang for F# Developers
#2241	Dec 21 (Wed)	Luis Quintanilla	Accept Webmentions using F#, Azure Functions, and RSS Introduction
#2242	Dec 21 (Wed)	Flavio Colavecchia	F# as your first functional programming language
#2243	Dec 22 (Thu)	Florian Verdonck	The oak sleeps in the acorn
#2244	Dec 22 (Thu)	Sean G. Wright & Kyle McMaster	Everything is Functions
#2245	Dec 23 (Fri)	Mukund Raghav Sharma (Moko)	Bayesian Optimization for Performance Tuning in FSharp
#2246	Dec 23 (Fri)	András Jankó	Compiling to JavaScript dynamically with WebSharper
#2247	Dec 24 (Sat)	Paweł Stadnicki	Distance Type Provider
#2248	Dec 24 (Sat)	Kirk Shillingford	From Script to Scaffold in F#
#2249	Dec 25 (Sun)	@BigX_	Using F# to help solve Wordle
#2250	Dec 26 (Mon)	Eriawan	What’s new in F# 7 and some tips (with BenchmarkDotnet)
#2251	Dec 27 (Tue)	David Dawkins	Sutil Oxide: A toolkit for building IDE-style web applications, using Sutil
extra	Dec 27 (Tue)	@dpego	Functional, reactive Point of sale with WebSharper
#2252	Dec 28 (Wed)	Alfonso Garcia-Caro
extra	Dec 28 (Wed)	Marius Fersigan
#2253	Dec 29 (Thu)	Adam Granicz	Full-stack F# with charting, reactive forms, and more under 300 LOC with WebSharper
#2254	Dec 30 (Fri)	Matt Eland	Machine Learning in .NET with F# and ML.NET 2.0
#2255	Dec 31 (Sat)	Kai Ito	F# in strange places: Supabase edge functions
#2256	Jan 01 (Sun)	FSSF

F# Advent Calendar is a long tradition in F# community

• F# Advent Calendar in English: 2020, 2019, 2018, 2017, 2016, 2015, 2014
• F# Advent Calendar (in Japanese): 2020, 2019, 2017, 2016, 2015, 2014, 2013, 2012, 2011, 2010

that became an inspiration for C# Advent Calendar and for Q# Advent Calendar and many others.

Christmas is approaching again, and now is the time to prepare our spirit for it with the goodness of F#. Please join, reserve one of 62 slots and spread your thoughts and love to F# with the community.

This time you also have a possibility to support me (the host) with some coffee. This is optional but very appreciated if you like an event 😁.

Join F# Advent Calendar today!

Rules

1. Choose F# related topic for your blog post and reserve the slot on Twitter or leave a comment to this post. Please note that you do not have to announce the topic until the date (but you can).
2. Prepare a blog post in English.
3. Publish your post on a specified date (according to the calendar).
4. Post the link to your post on Twitter with hashtags #fsharp and #FsAdvent.

Advent fun with F# and Advent of Code

ID	Date	Author	Post Title
#2101	Nov 28 (Sun)	Matthew Thornton	Typesafe F# configuration binding
#2102	Nov 28 (Sun)	Paweł Stadnicki	Practical Open Data: Commuting to Christmas Markets in Berlin with F#
#2103	Nov 29 (Mon)	Kirk	Semantics, Not Syntax; Developer empowerment using functional-first programming
#2105	Nov 30 (Tue)	Lilith	Fedis
#2107	Dec 01 (Wed)	Phillip Carter	How to use OpenTelemetry with F#
#2108	Dec 01 (Wed)	Ramón Soto Mathiesen	Poor man’s Kafka (stream-processing bus)
#2109	Dec 02 (Thu)	Matthew Crews	F# Loves Mutation
#2111	Dec 03 (Fri)	remmah	Setting up FNA for game development with F#
#2112	Dec 03 (Fri)	Angel Munoz	Dealing with workflows in F#
#2113	Dec 04 (Sat)	Ian Russell	Using Discriminated Union Labelled Fields
#2115	Dec 05 (Sun)	Dave Curylo	Defining a Software Specification
#2117	Dec 06 (Mon)	Urs Enzler	Our journey to F#: The effect of F# on our (unit) tests
#2118	Dec 06 (Mon)	Dave Thomas	MonoGame Resurrected
#2119	Dec 07 (Tue)	Florian Verdonck	Fantomas Daemon
#2120	Dec 07 (Tue)	Paul Biggar	Benchmarking F#6 Tasks
#2121	Dec 08 (Wed)	Mårten Rånge	Fast data pipelines with F#6
#2122	Dec 08 (Wed)	Martin Grotz	Serene Sitting with Sutil
#2123	Dec 09 (Thu)	Steffen Forkmann	Santa and the container apps in the cloud
#2124	Dec 09 (Thu)	Brett Rowberry	An F# Dev’s Perspective on Clojure
#2125	Dec 10 (Fri)	John Azariah	Scientific Computing with F# – Post 1 : Introduction – Post 2 : TSP – Post 3 : BRKGA – Post 4 : Solving TSP with BRKGA – Post 5 : Conclusion
#2126	Dec 10 (Fri)	Matt Gallagher	Using Fable.Lit for Fable apps
#2127	Dec 11 (Sat)	Ronald Schlenker	PrettyFsi is an F# Interactive table printer
#2128	Dec 11 (Sat)	Atle Rudshaug	Exploring your crypto with F#
#2129	Dec 12 (Sun)	Sudipta Mukherjee	Matching cookies to playing cupid with F#
#2130	Dec 12 (Sun)	Cameron young	[no reply]
#2131	Dec 13 (Mon)	Iwan van der Kleijn	[no reply]
#2132	Dec 13 (Mon)	Brett Hall	Akka for Advent
#2133	Dec 14 (Tue)	Mark Allibone	Advent fun with F# and Advent of Code
#2134	Dec 14 (Tue)	Luis Quintanilla	Sending Webmentions with F#
#2135	Dec 15 (Wed)	Chester Burbidge	Interactive code runner with FSCS and SAFE stack
#2136	Dec 15 (Wed)	Gianni Bossini & Jacek Wronski	Sudoku in F#: a functional story
#2138	Dec 16 (Thu)	Angel Munoz	Building a Webpack alternative in F#
#2139	Dec 17 (Fri)	Kunjan Dalal	Plotly, F# and Response of India to Covid Crisis
#2140	Dec 17 (Fri)	Jérémie Chassaing	Functional Event Sourcing Decider
#2141	Dec 18 (Sat)	Eriawan	Initial quick dive into F# 6 task computation expression
#2142	Dec 18 (Sat)	Asti	Contracts for Event Sourced Systems with FsCodec
#2143	Dec 19 (Sun)	David Dawkins	Writing an Appwrite Web App in F#
#2144	Dec 19 (Sun)	@davidglassborow	FSharp DSL for POV
#2146	Dec 20 (Mon)	Riccardo Terrell	Concurrent Pipeline with .NET Channels
	Dec 20 (Mon)	Vitalii Braslavskyi	Building a Flexible Deployment System for Grammarly for Windows using F# and AWS Lambda
#2147	Dec 21 (Tue)	Bartosz Sypytkowski	Let’s write async-compatible read/write lock
#2148	Dec 21 (Tue)	Édgar Sánchez Gordón	Algorithms Illuminated in F#, the beginning
#2149	Dec 22 (Wed)	Dave Shaw	Giraffe Development in 2022
#2150	Dec 22 (Wed)	Jimmy Byrd	[delayed]
#2151	Dec 23 (Thu)	Mukund Raghav Sharma (Moko)	Perf Avore: A Performance Analysis and Monitoring Tool in FSharp
#2152	Dec 23 (Thu)	Jason Down	All You Can Eat Agents
	Dec 23 (Thu)	Danyl Novhorodov	Lightweight microservices with F# and ZeroMQ
#2153	Dec 24 (Fri)	Marcin Golenia	.NET 6 Minimal apis for F# devs, what we get? (including testing)
#2154	Dec 24 (Fri)	József Uri	Reactive forms with WebSharper.Forms
	Dec 24 (Fri)	Devon Burriss	A simple FP architecture
#2155	Dec 25 (Sat)	Patrick Kelly	Real World F# Interop
#2156	Dec 26 (Sun)	Ryan Coy	There is No Magic – Computation Expressions
#2157	Dec 27 (Mon)	Stachu Korick	Intro to reMarkable; Motivation; Getting Started The reMarkable Hacking Ecosystem reMarkable.fs
#2158	Dec 28 (Tue)	András Jankó	Client-Server Routing with WebSharper
#2159	Dec 29 (Wed)	Adam Granicz	Content-managed WebSharper apps with custom web controls and templating
#2160	Dec 30 (Thu)	Aaron Muylaert	[no reply]
#2161	Dec 31 (Fri)	Kai Ito	Using Sutil to develop a real world application
#2162	Jan 01 (Sat)	FSSF	Welcome to 2022!

F# Advent Calendar is a long tradition in F# community

• F# Advent Calendar in English: 2019, 2018, 2017, 2016, 2015, 2014
• F# Advent Calendar (in Japanese): 2020, 2019, 2017, 2016, 2015, 2014, 2013, 2012, 2011, 2010

that became an inspiration for C# Advent Calendar and for Q# Advent Calendar and many others.

This year was hard for all of us, we definitely deserve Christmas spirit and F#  goodness. Please join, reserve one of 60 slots and spread your thoughts and love to F# with the community.

Join F# Advent Calendar today!

Rules

1. Choose F# related topic for your blog post and reserve the slot on Twitter or leave a comment to this post. Please note that you do not have to announce the topic until the date (but you can).
2. Prepare a blog post in English.
3. Publish your post on a specified date (according to the calendar).
4. Post the link to your post on Twitter with hashtags #fsharp and #FsAdvent.

Calendar

ID	Date	Author	Post Title
#2001	Nov 29 (Sun)	Paweł Stadnicki	Code as a Vote
#2002	Nov 29 (Sun)	Logan Mortimer	Cellular Automata in F#
#2003	Nov 30 (Mon)	Onur Gümüş	Fable Web Components
#2004	Nov 30 (Mon)	Esteban Solano G.	Creating your first GitHub codespace for F# and .Net 5.0
#2005	Dec 01 (Tue)	Ian Russell	Introduction to Partial Function Application in F#
#2006	Dec 01 (Tue)	Tyson Williams	Converting asynchronous cancellation from C# to F#
#2007	Dec 02 (Wed)	Ambika Eshwar	Parsing Programming Languages with FParsec
#2008	Dec 02 (Wed)	Tonino Lucca	A mouse in a box
#2009	Dec 03 (Thu)	Brett Rowberry	F# Compiler Messages
#2010	Dec 03 (Thu)	Ryan Palmer & Isaac Abraham	Validation with F# 5 and FSToolkit
extra	Dec 03 (Thu)	Paweł Stadnicki	⏸ Delayed till Dec 13
#2011	Dec 04 (Fri)	Marcin Golenia	F# Dependency Injection – how to compose dependencies with partial application and don’t fail with tests
#2012	Dec 04 (Fri)	Phillip Carter	How to make an F# Code Fixer
extra	Dec 04 (Fri)	Jérémie Chassaing	Applicative Computation Expressions – 3
#2013	Dec 05 (Sat)	Asti	F# Interactive now with Stories!
#2014	Dec 05 (Sat)	Jimmy Byrd	FsToolkit.Errorhandling 2.0
extra	Dec 05 (Sat)	Garth Fritz	Dependency Injection Using Flexible Types and Type Inference
#2015	Dec 06 (Sun)	Angel Munoz	F#’s MEAN
#2016	Dec 06 (Sun)	Mårten Rånge	Church Encoded Lists
extra	Dec 06 (Sun)	Andrew Meier	F# EventStoreDB Subscription
#2017	Dec 07 (Mon)	John Azariah	Bouncing around with Recursion
#2018	Dec 07 (Mon)	Sean Kearon	Long-running business processes in F# with Rebus on Azure
extra	Dec 07 (Mon)	Daniel Hardt	Fable.React.WebComponent
#2019	Dec 08 (Tue)	Frank A. Krueger	Functional Motor Control
#2020	Dec 08 (Tue)	Pim Brouwers	F# on the Web: A guide to building websites with Falco, .NET 5.x and ASP.NET Core
extra	Dec 08 (Tue)	Joffrey Dalet	F#, Back-End, and Thread-Safe Data Collection using MailboxProcessor
#2021	Dec 09 (Wed)	Patrick Kelly	Designing Around F# Interop
#2022	Dec 09 (Wed)	André Slupik	F#’s Stack Overflow community is amazing
extra	Dec 09 (Wed)	Matthew Crews	Why I Love F# for Mathematical Planning
#2023	Dec 10 (Thu)	Erik Schierboom	Timing code using computation expressions
#2024	Dec 10 (Thu)	Justin Hewlett	To Annotate, or Not to Annotate?
extra	Dec 10 (Thu)	Matthew Herman	Functional Gift Wrapping
#2025	Dec 11 (Fri)	Dave Shaw	SnowPi in F#
#2026	Dec 11 (Fri)	Joe Miyamoto	Prototyping generic Bitcoin Smart contract
#2027	Dec 12 (Sat)	Eriawan	F# Advent 2020: Revisiting Windows Forms and WPF in .NET 5.0 and hello F# 5.0
#2028	Dec 12 (Sat)	Dudley	⏸ Delayed till 20th
#2029	Dec 13 (Sun)	Stan Janssen	Plugin architecture in F#
#2030	Dec 13 (Sun)	Luis Ferrao	The 40 year old logging virgin
#2031	Dec 14 (Mon)	Mark Pattison	Map Data Visualisation with F# and Fable
#2032	Dec 14 (Mon)	Luis Quintanilla	Train an image classifier using F# and ML .NET
#2033	Dec 15 (Tue)	Damian Płaza	A Type of Happiness Inc.
#2034	Dec 15 (Tue)	Florian Verdonck	Gitpod & Snowpack
#2035	Dec 16 (Wed)	Mark Allibone	Working with SignalR and Fabulous
#2036	Dec 16 (Wed)	Mikhail Shilkov	Farmer or Pulumi? Why not both!
extra	Dec 16 (Wed)	Martin Freedman	Exercism, List.scan and the Twelve Days of Xmas
#2037	Dec 17 (Thu)	Reed Copsey, Jr.	F# Basics – Result<‘a>: or How I Learned to Stop Worrying and Love the Bind
#2038	Dec 17 (Thu)	Kunjan Dalal	Differentiating Web Assembly with F#
#2039	Dec 18 (Fri)	Istvan	Running ASP.Net web application with Falco on AWS Lambda
#2040	Dec 18 (Fri)	Jorge Gueorguiev	Introducing F# onto your systems
#2041	Dec 19 (Sat)	Ryan Coy	An F# Primer for curious C# developers.
#2042	Dec 19 (Sat)	Riccardo Terrell	Build a Recommendation engine with ML.NET and F#
#2043	Dec 20 (Sun)	Scott Wlaschin	Six approaches to dependency injection
#2044	Dec 20 (Sun)	David Nazarov	Mission Asyncable – The Basics of Asyncs – Part 1: Cancellation
#2045	Dec 21 (Mon)	Phil Trelford	Fable DJ Drops
#2046	Dec 21 (Mon)	Edgar Rodríguez	🚫Cancelled
#2047	Dec 22 (Tue)	Evgeniy Andreev	⏸ Delayed
#2048	Dec 22 (Tue)	Krzysztof Madej	Deploying Farmer template from Azure DevOps
#2049	Dec 23 (Wed)	MokoSan	Bayesian Inference in FSharp
#2050	Dec 23 (Wed)	JaggerJo	.NET on a Raspberry Pi Zero
#2051	Dec 24 (Thu)	Jon Wood	ML.NET Predictions on the Web in F# with the SAFE Stack
#2052	Dec 24 (Thu)	Devon Burriss	Creating a Prometheus parser: Fennel
#2053	Dec 25 (Fri)	Gregor	Save yourself from Krampus with ML.NET and F#
#2054	Dec 26 (Sat)	Jamie Dixon	Looking at SARS-CoV-2 Genome with F#
#2055	Dec 27 (Sun)	Matt Eland	How Programming Languages Change How You Think
#2056	Dec 28 (Mon)	Kevin Avignon	The F# Mentorship Schedule Planner
extra	Dec 28 (Mon)	Mark Seemann	An F# demo of validation with partial data round trip
#2057	Dec 29 (Tue)	Chester Burbidge	Rapid app development with F# and AWS Amplify
#2058	Dec 30 (Wed)	Adam Granicz	Variations for a WebSharper shopping cart – Part I
#2059	Dec 31 (Thu)	Kai Ito	Improving Real-time communication using Fable.SignalR
#2060	Jan 01 (Fri)	FSSF	Thank you, and Welcome to 2021!