Design Patterns

Proposed book about Event Sourcing & CQRS

Thomas Jaeger .NET, Book, C#, Design Patterns, Domain Driven Design, Event Sourcing, Programming

For years, I wish I had a source that I can direct people to learn more about Event Sourcing & CQRS. Greg Young never created a book, sadly. The difficulty in Event Sourcing & CQRS is not so much the technical side but, as usual, the people you need to convince and work with. Typically, Event Sourcing allows for capabilities in your software that are extremely hard or almost impossible to do with old style software development. It is fairly easy to convince executives, product, sales, etc. that these new capabilities and insights for your customers can easily beat competition. So, why is Event Sourcing not used in like 85% of all software projects? I believe that there are different reasons but at the core, where can people go to? The Web? The Web shows all sorts of different views and many of them show inexperience and brushing Event Sourcing off as “too difficult” or “increased complexity”. WTF? Software by it’s definition is hard to do properly if you stay aligned with the business and the vision your organization has. I argue that Event Sourcing makes this actually easier, not harder!!! The CRUD virus shows its ugly head again!

So, after years of not having a great source for people to direct to, I’ve been seriously thinking of writing a book about Event Sourcing and CQRS. I have not pulled the trigger because I know this a huge time commitment. However, I did create a six page table of contents and surprised myself of how much information can and should be shared on this topic. This book would be very comprehensive and covers Event Sourcing from every angle including the business and customers side and not just the technical side.

My question would be, are you interested in this type of book?

Design things to be replaceable, not reusable!

Thomas Jaeger Architecture, AWS, Cloud Computing, Design, Design Patterns, Domain Driven Design, Microservices, Serverless

I love this quote by Andy Hunt

“I find aiming to make things “replaceable” far better than making things reusable. Reusable means you’re fortune-telling, trying to divine an unknowable future.”

This is what I’m aiming for as well especially when you bring in the Sacrificial Architecture. Love it.

As you create your architecture, design all components to be replaceable, not reusable. This is a whole lot easier nowadays with AWS and Lambda creating serverless masterpieces, for example.

Serverless Microservices Online Courses

Thomas Jaeger .NET, Architecture, AWS, C#, Cloud Computing, Course, CQRS, Design, Design Patterns, Domain Driven Design, DynamoDB, Event Sourcing, Serverless, SQS , , , , ,

Update 04/03/2019: I have completed the FREE course: “Why you need serverless microservices, yesterday!“. Enroll for FREE!
At the moment, I’m working on four online courses in the following order:

 

“Why You Need Serverless Microservices, Yesterday“, FREE Course

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In this course I will walk you through the many benefits of creating serverless microservices instead of the traditional node / instance approach including the use of containers. There are more than enough things to worry about when you want to create a new cloud system or transform a legacy system to operate in the cloud.

From a business point of view, there are huge benefits in going serverless rather than instance based (including containers). A very large jump in business agility can be achieved through focusing on the problems and opportunities rather than the technical jungle of traditional computing solutions.

From a technical point of view, it is almost nirvana where you can eliminate many points of failures in the architecture.

 

“How To Build An Event Store”, Paid Course

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Your event store is the heart of an event sourced system. The event store is the source of truth for all business events. It needs to be able capture and replay all domain events in your system reliably and with great performance.

In this course, I will walk you through building an event store that you can re-use in your own projects. In addition, I will walk you through building a read model that allows you to query domain events from the read model.

I will also go through why building your own event store has many more advantages over using a third-party event store.

We will be building the event store in AWS DynamoDB but you can apply the design to a traditional RDMS SQL storage just as well. I will go over the pros and cons in doing so.

 

“Architecting And Designing Event Based Microservices”, Paid Course

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Learn the details on how to design and architect event based microservices using Domain Driven Design (DDD), Event Storming, CQRS, and EventSourcing techniques. I will show you how best combine many principles, patterns, and techniques to create an architecture with as few points of failures as possible and still deliver a great solution.

What you will learn can be applied to cloud based systems but also to traditional, on-premise systems. The benefits are great in either environments.

Whether you are designing a new system in a greenfield environment or transforming a legacy system, I will show tips & tricks that you can use depending which type of project you are in.

 

“Implementing A Serverless Microservice in AWS”, Paid Course

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Learn the details on how to implement a serverless microservice in AWS using Domain Driven Design (DDD), CQRS, and EventSourcing techniques.

We will build a fully functioning billing system in AWS using Visual Studio and C# .NET Core. Even if you are not familiar with C# and .NET Core, you will learn a lot of practical tips on using the different AWS services including building fully automated CI/CD pipelines.

 

I’m still working on these courses but I’m planning on publishing “Why You Need Serverless Microservices, Yesterday” and “How To Build An Event Store” first.

My New YouTube Channel

Thomas Jaeger .NET, Amazon S3, Architecture, AWS, C#, Cloud Computing, Course, CQRS, Design, Design Patterns, Domain Driven Design, DynamoDB, Event Sourcing, Persistence, Programming, Serverless, YouTube

I just created my new YouTube channel “Creating Great Software”. Have a look.

I will be publishing videos about creating great software including serverless computing in AWS. In addition, I will be publishing my STRONG opinions about the state of the software industry from time to time.

I’m super excited about this new channel and I’m looking forward in seeing your feedback. See you there!

Serverless System Course

Thomas Jaeger .NET, Amazon S3, Architecture, AWS, C#, Course, Design, Design Patterns, Domain Driven Design, DynamoDB, Event Sourcing, Persistence, Programming, Serverless, SQS

In the past 27 professional years, I have been fortunate enough to gain a lot of experience and wisdom in 10 different software industries. These experiences are not just successful accomplishments but also plenty of failures and mistakes made along the way. It is ok to make mistakes as long as you learn from them, only then you will gain true wisdom in anything you do.

Over the years, I have always thought, “If I could gather a small team, I could share my knowledge and we can create great things“. Due to many circumstances, I never had the opportunity to mentor a small team and being in full control on what we would create. By full control I mean free from politics and other constraints. The sort of freedom you need to create and explore ideas without worrying about budgets, timelines, etc. When you can foster such an environment, great things get invented. Just look at the past successes in Silicon Valley.

How can I share my experiences and wisdom most efficiently and help you achieve your goals much more rapidly rather than doing it alone? I have decided it is time to create an online school where I can share all my knowledge and wisdom from the software industry. Well, how about an online course that is very deep in all aspects. An online course that would teach you the birds eye view of concepts and then drills down into the very deep aspects of it. A course that could show you actually how to put the conceptual components together in a very cohesive way. All the different pieces put together in an architecture that makes real sense and is practical and maintainable. We’ll leave the fluff out and concentrate on the entire system starting from a users perspective and walk backwards into the technical implementation details. In short, a

Serverless System Master Class

This master class would be extensive and we will go into a lot of details until we have built a working system that you could use in your future projects. As a minimum, you would learn a lot of concepts and software architecture. Since technology is always changing, I believe that the concepts will be more valuable then the implementation details in the course. In addition, how you bring these concepts together and why are extremely important because in your day-to-day work, you will have constraints that you need to work with and make compromises. There is no perfect architecture and even in this master class, you will touch on many different options one could take and why.

Please let me know if you are interested in the Serveless System Master Class. I would love to hear your feedback as I work on the course. I plan to post regular updates on my blog here.

Leave a comment below or contact me directly at thomasjaeger at gmail dot com and let me know your level of interest, please!

Software Quality

Thomas Jaeger .NET, Assembly, C#, Cloud Computing, Delphi, Design Patterns, Domain Driven Design, MASM, Programming

As you may know, I’m working on an open source project called Visual MASM which is an IDE to create assembly applications for Windows just as easy as the Delphi or Visual Studio IDEs provide. Well, at least that is my goal.

I was looking back on why I want to create a commercial application in the Real Estate industry using my very own assembler IDE and was reading what I wrote about using assembly in the first place: Why Assembler?

There are so many languages and tools available today in order to program a solution. I have used almost all of them in the past 32 years of programming. Why on earth use assembly for Windows? For a clear business reason, Windows “owns” the world wide market and is used in over 90% of computers as of today. Never mind Linux, MacOS, etc. I mean, Windows “owns” it. Period. It makes total sense to develop for Windows when you create a commercial solution.

The fact that Windows owns the market; however, is still secondary to my motivation to create a commercial application for Windows using the assembly language. The main reason is really: Software Quality.

Quality in general, in my opinion, means paying attention to every detail. Because one pays attention to every detail, you are forced to make many decisions. As you abstract into higher languages, these decisions have been made for you. Because of this, you are no longer able to make detailed decisions. In order to pay attention to the detail of software quality, you have passion to follow through with it. Being able to make these detailed decisions also offers freedom and control of the creation process. That’s the ultimate power of high, software quality. You must have control in order to make software quality decisions.

So, paying attention to detail with passion is equivalent to high software quality. It is that simple.

 

Updated C# Reference Implementation

Thomas Jaeger .NET, Architecture, C#, Design, Design Patterns , , ,

I have updated my C# reference implementation and included FluentValidation on some of the DTO objects. I also updated the ErrorMap to include validations on the server side as well as on the WPF client side. This version also includes a sample SQL Server Persistence Provider. As always, you can get the latest code on my GitHub repo.

Slides for Sacramento .NET User Group

Thomas Jaeger .NET, Design Patterns , ,

Update 04-05-2015: I completed the SQL Server Provider. Latest code is on GitHub.

I had a lot of fun presenting last night at the Sacramento .NET user group. It was great to hear that people learned a lot and are looking forward in incorporating the things they have learned about the Provider Model design pattern and object persistence in general into their own projects. The slides are available for download here. The source code of the entire reference implementation is available here. I will be finishing up the SQL Server provider within the next few days and make it available in my GitHub repo.

Object Persistence Reference Implementation

Thomas Jaeger .NET, AWS, C#, Cloud Computing, db4o, Design, Design Patterns, Persistence, SimpleDB , , , , ,

I’ve been updating my reference implementation in the last few days. I’m actually using this reference implement in my own projects. You can download the latest version on my GitHub repo.

This is a complete .NET C# reference implementation to help you jump start a service oriented system running in a cloud environment such as Amazon’s EC2 or on-premis clusters.

This reference implementation shows you how to build a client and the server side. The client side is a sample WPF application that communicates via http REST requests using JSON payloads to the service side. Of course, you can use any type of client as long as the client can communicate via http and REST based JSON’s.

The service side is using a Web API 2 service layer that communicates to a central domain model. The service side demonstrates how to handle exceptions and edge cases and how to communicate failure to the client.

The persistence layer demonstrates the extreamly powerful provider pattern to store the domain objects into the following databases:

  1. db4o (an object database)
  2. Redis (a NoSQL database)
  3. SimpleDB (a NoSQL database)
  4. SQL Server (comming soon)

Please note that the entire system has no knowledge on how the objects are stored. All implementation details are in the individual providers listed above. This means that you can switch the persistence provider without having to recompile and therefore switch a running system from one persistence store to another.

I will try to create a sample SQL Server provider soon.

appsworld North America 2015 at Moscone Center West, San Francisco

Thomas Jaeger .NET, AWS, C#, Cloud Computing, Delphi, Design, Design Patterns, iOS, iPhone, Objective-C, Persistence, Presentation, Redis , , , , , ,

appsworldlogo

I’m a confirmed speaker at the appsworld North America 2015 at Moscone Center West, May 12-13 in San Francisco, CA.  Discover the future of multi-platform apps. See all confirmed speakers. This sure will be an exciting event. I’m still working on my presentation that will include Redis, Amazon AWS, C#, and more. I will see you there.