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My name is Oskar Dudycz. From over 13 years, I'm creating software close to the business.
I run workshops and training about Event Sourcing, CQRS and event-driven architectures.
I'm co-maintainer of Marten OSS library that allows implementing Event Sourcing.
On the blog, I share my knowledge of how to create good, modular applications pragmatically.
Notes about C# records and Nullable Reference Types
In the last months, I spent quite some time playing with C# records and Nullable Reference Types. I was hoping that thanks to them, I would…
In what language are programmers writing?
Wikipedia states that there are around 700 programming languages. Some are more popular. Some are less. But what language do programmers…
Form a wall! And other concerns about security
There were 0.3 seconds left till the end of the NBA match. Detroit Pistons were leading by a single point against San Antonio Spurs. The…
Let's take care of ourselves! Thoughts on compatibility
In the last year, the word responsibility is used in all possible ways. Responsibility for us, for others. We can be heroes wearing masks…
How to get the current entity state from events?
Today I’d like to go back a bit to the basics of Event Sourcing. I recently realised that I often cover more advanced topics. So sometimes…
When not to use Event Sourcing?
Event Sourcing is perceived as a complex pattern that’s challenging to learn. Typically it’s matched with the financial industry or big…
Generic does not mean Simple
As you know, I am a fan and practitioner of CQRS.. I believe that it is falsely considered as complicated. In my opinion, it can help even…
Structural Typing in TypeScript
When we talk about typing in programming languages, we usually divide it into static and dynamic. Static typing is checked at the compile…
When Agile is not enough
Today I want to invert the classical pro-agile drawing. Let’s talk about the devaluation of functionality that occurs in Agile projects. In…
How to scale projections in the event-driven systems?
People want to scale up everything. In the past, the recipe for everything was to buy a larger server. Today, the answer is to add another…
Why are senior devs afraid to code?
The job interview is a stressful situation, usually for both parties. Some time ago, I had to recruit senior developers. I had the idea to…
How to create a custom GitHub Action?
As you may know, I’m a fan of documentation. I wrote a few practical tips on this topic on the blog: “How to create projections of events…
Memoization, a useful pattern for quick optimization
Today I would like to show you a simple programming pattern that can be useful for quick code optimization. This pattern is called…
How using events helps in a teams' autonomy
Autonomy is the Holy Grail for the management of multiple teams. At least that’s how it’s perceived; it’s not easy to get the right balance…
How to enhance and configure your site search with Algolia?
Some time ago, I wrote on how to create documentation without the pain (read it here). Documentation is something that has been one of the…
Events should be as small as possible, right?
TV size? The bigger, the better. Debt amount? Opposite. It’s hard to find the right size that suits all. How big should the event be? What…
How to create projections of events for nested object structures?
Did you ever feel so encouraged so much that you immediately thought, “This is great, let’s do it!“. I’m sure you did. I’m also sure that…
How to get started with Open Source?
As you may know, I’m an active Open Source contributor. Since December 2020, I’m working full-time on the Open Source project EventStoreDB…
How to successfully do documentation without a maintenance burden?
Developers like to complain about the lack of documentation. They complain even more when they have to write it. No programmer wants to do…
How money in Cloud impacts Architectural decisions?
It’s intriguing how our perspective on software development changed in the last few years. We transformed from the on-premise age to the…
Can command return a value?
Last week I busted common myths and explained facts about CQRS. Today I’ll continue my effort. I tackle one of the most common questions…
CQRS facts and myths explained
I’m sure that you know a lot of Urban Legends. They usually start with “hey, my friend’s cousin saw that…” or “you know, I’ve read such…
Why Partial<Type> is an extremely useful TypeScript feature?
If TypeScript were a friend of mine on Facebook, then I’d mark our relation as complicated. It’s a history of love & hate, or rather hate…
How to set up a test matrix in XUnit?
Each country has the go-to place for hiding from daily struggles. In Poland, we have Bieszczady. It’s a mountain range that’s also the…
What's the difference between a command and an event?
What’s the difference between a command and an event? The answer seems apparent, but let’s see if it’s straightforward. The command…
Saga and Process Manager - distributed processes in practice
What can go wrong with distributed systems? Everything! I like to compare distributed systems to Rocky Balboa fighting the last round with…
What if I told you that Relational Databases are in fact Event Stores?
Are you one of those people saying that Event Sourcing is detached from reality? Do you think that you don’t need such extravagance, as you…
What texting your Ex has to do with Event-Driven Design?
We sometimes feel melancholic, blue and a bit messy. When we enhance those feelings with “gummy berry juice” then various dubious ideas come…
Sociological aspects of Microservices
Last week, I started writing about the topic of cutting systems into microservices (read more here). I was sceptical about the frequent…
How (not) to cut microservices
Today, I’m holding a keyboard in one hand and scissors in the other. What do I need these scissors for? According to the post title, I would…
Bring me problems, not solutions!
“Bring me solutions, not problems!” I’ve heard this sentence multiple times from Business and management. You’ve heard it too, haven’t you…
Outbox, Inbox patterns and delivery guarantees explained
Yesterday I was asked by Cezary about the transactional outbox pattern sample implementation. My answer was: The question was short - answer…
How to (not) do the events versioning?
Developers that are not running a system in production might call themselves lucky. They can live in their perfect world. It is a world…
Optimistic concurrency for pessimistic times
Apparently, one of the worst things you can wish someone is “may you live in interesting times”. In these interesting times of ours, I…
Why a bank account is not the best example of Event Sourcing?
While explaining the Event Sourcing, bank account balance calculation is a common starting point. I claim that even though it sounds right…
Revolution now!
Did you ever get an offer that someone will pay you for what you are currently doing as a hobby? What would be your decision if that would…
Architect Manifesto
“Architects are not needed anymore. Those days are gone!” “We’re agile - we’re not doing waterfall, so we’re not designing upfront.” “We…
