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Intro

This web-site explores the idea that data has a dual nature - a stream (flow) and a particle (id) - an idea inspired from physics that light has the dual nature - wave and particle. It is collection of design notes on multiple, seemingly unrelated, topics that follow from this core assumption.

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Performance Testing a New CRM

Performance testing  is challenging, frustrating, often underestimated typically getting attention only after an incident. How did we the performance test and what did we learn during the development and implementation of  web-services for a new CRM system?
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View - A Functor for Web App Design

This blog is about practical applications of Category Theory to the development of Java + Spring applications. I am looking at a design approach to simplify the development of web applications. Traditionally, this kind of back-office application is based on the Web 1.0 technology stack, using Spring Boot and Thymeleaf. My approach is to keep using Spring Boot but replace the generation of HTML with J2HTML and higher-order views. From a Category Theory point of view, we can look at web applications as mappings from the Category of Business Entities and the Category of UI Widgets. If we go one step further, both business entities and UI widgets are mapped to Java classes. Thus, we can view a web application (or a part of it) as an endofunctor in the Category of Java Classes. We define the View-functor as follows: domain(V) - Java classes representing business entities - e.g., Invoice, User - and, codomain(V) - Java functions that render the business entity as a DomContent object (DomCont
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What Can Category Theory Do for Me?

Category Theory is one of the hot topics in computer science. There are many blogs, youtube videos and books about it. It is an elusive subject, with the potential to be the ultimate unifier of everything (math, quantum physics, social justice), to allow us to write the best possible programs and many other lofty goals. I decided to explore the field and see how it can help me. Below is a summary of 12 weeks of reading and watching presentations about Category Theory. It took me some time to select the study material. In the end I decided to use David Spivak’s book (Category Theory for Sciences, David Spivak, 2014) and the youtube recording of a 2017 workshop. These provided both a rigorous approach and a lighter version in the youtube videos. In parallel we explored other sources for a more practical perspective. The CTfS book is a systematic introduction to Category Theory, with definitions and proofs. I liked that, it is a solid foundation. The examples are mostly from math (Set,
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