Skip to main content

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.

Calin Groza

Popular posts from this blog

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...

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?

On Defining Messages

“Defining Message Formats” is the title of a message posted on the Service Oriented Architecture mailing list [1]  which attracted a lot of attention.  The post summarizes  the dilemma faced by solution architects when they have to define a service interface: 1. Base the internal message format on the external message standard (MISMO for this industry). This message set is bloated, but is mature, supports most areas of the business, and is extensible for attributes specific to this company and its processes. 2. Create an XML-based message set based on the company's enterprise data model, which the company has invested a great amount of money into, and includes a very high percentage of all attributes needed in the business. In a nutshell, we've generated an XML Schema from ER Studio, and will tinker with that construct types that define the payloads for messages. 3. Use MISMO mainly for its entity definitions, but simplify the structure to improve usability. We benefit fr...