Next Meetup

Event Sourcing with F# and Azure Cosmos DB
"I wish I knew this last year! Nobody told us it's important to store this value. What just happened to our system?!" Does this sound familiar to you? If so, perhaps event sourcing is right for your application. Why should you use events? Why with F#? And what about versioning? Let me take you on a journey through the development of a web-based event sourcing application in F# & Azure Cosmos DB. I'll show you all the pain points and dead ends we went through and how we end up with a sane design. Warning: this talk contains some bad decisions you definitely do not want to repeat. Please also register with our hosts Skills Matter: G-Research will again be kindly sponsoring pizza for the evening, and the CodeNode bar will be open. Roman Provazník is a .NET developer, software architect and the founder of the Czech F#/functional .NET community called FSharping. He has been developing applications for more than 18 years using languages like Pascal, Delphi, PHP, C# and F# but still feels the same excitement for computers as he did as a young kid touching a Commodore 64 keyboard for the first time. With his background of 3 years as a local radio station presenter (which proves IT is not only for introverts), he is always ready to chat about the things he loves: F#, functional programming, domain-driven design, event sourcing systems, web development and drums. You can often see him hanging around the F# community he helps to maintain and grow.

Skills Matter at CodeNode

10 South Place, EC2M 7EB · London

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What we're about

F#unctional Londoners is a meetup group that aims to bring together Londoners with an interest in functional programming with F#. Topics include: - Essentials of functional programming and F# - Assessing what kind of projects F# is well suited for - or not - Using F# alongside other languages and libraries - Asynchronous and parallel programming - Data visualisation - Scientific programming - Numerical methods and optimisation - Financial modelling

As an affiliated user group of (, the F# Software Foundation, we strive to build a great community of passionate people who care deeply about F#, and want to make our community a safe and welcoming place for everyone. We expect everyone attending our events to be respectful, open, and considerate, and to follow the F# Software Foundation Code of Conduct ( If someone's behavior makes you feel uncomfortable or unsafe in any way, please report the issue by emailing

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