The Theory of Constraints (TOC) is a management philosophy and methodology developed by Eliyahu M. Goldratt. It focuses on improving organizational performance by identifying and addressing constraints, which are bottlenecks or limiting factors that impede the system's ability to achieve its goals.

I recently stumbled upon a Library called FastEndpoints while doing research and it immediately struck me as something I wanted to learn more about. I had started experimenting with Minimal APIs at the time. While I liked that Minimal APIs lower the entry point for simple API creation and are significantly more performant than MVC Controllers, they quickly turn your program.cs file into a jumbled mess with anything beyond trivial. The desire for code organization quickly pushes towards finding a sensible way to orient the code.

Not versioning APIs is one of the biggest issues I see with teams that attempt to implement a distributed architecture. Not supporting multiple versions of an API means all the teams are coupled together and requires downtime to deploy. I've actually seen where this is actually listed as a reason to use a monolith instead of a distributed architecture.

My early exploration and subsequent experiences with building a solution that leverage Marten.

If you have not run across Steeltoe, it is a set of libraries that address most of the cross cutting concerns you deal with when building microservices. Logging, Configuration, Health Checks, Traces, Service Discovery, etc.

Recently, I became aware of two other options in the .NET Service Bus space that I felt deserved a closer look. Rebus and Brighter. Since Rebus seemed to be similar to NServiceBus and MassTransit I started there.

Property encryption is one of my favorite NServiceBus features in that it provides a pattern for implementing message encryption as well as providing a concrete basis for addressing the concerns of compliance and security teams. Additionally, once your endpoint conventions are configured, it is easy to live with since it gets implemented only where necessary and in a consistent way.

One of the foundational features of NServiceBus is the support of multiple queuing technologies known in NServiceBus parlance as a Transport. NServiceBus transports encapsulate the logic required to connect to their respective queue technologies to produce and consume messages.

Testing is one of the more challenging aspects of message based systems and is probably one of the top reasons it is common to see http endpoints instead of messaging in microservices.

There are a number of subtle but important aspects of message based systems that are not apparent until after you have started building one and running it in production. One of those aspects is message headers. NServiceBus message headers contain metadata about each message that will help you correlate, route and trace the history of a message in your system.