Notes on software and the ideas behind it

Find the meaning
behind the code.

I’m Fred Yang. I write about software—how it works, why it behaves the way it does, and the ideas that make code easier to reason about.

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Working notes / 2026

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Architecture, reactivity, and the hidden relationships that shape frontend systems.

WF

Adding Workflow persistence service

<p> This can be done programatically or declaratively. Below is section of code that do it programtically. </p>
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WF

Adding Local service in WF

<p> There are two ways to add local service to workflow runtime, programatically or declaratively. Below is section of code that do it programatically. </p>
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WF

Local service(Data Exchange Service)

<p> WF also supports another kind of service known as a local service (sometimes called a data exchange service). This is a service that you design and implement yourself. A local service can serve...
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field note

ConditionalAcitivityGroup

<p> This Activity is like the combination of ParallelActivity and WhileActivity. The parent is ParallelActivity and the child is WhileActivity. </p>
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WF

Workflow Property

<p> Parameters can be defined for a workflow (or custom activity) in two ways. You can implement a normal .NET class property, or you can use a dependency property. The property value for a...
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