Blog:

My thoughts on software development.

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I have many interests in software development and I enjoy writing about then. As such my blog doesn't cover just one topic.

Using Factories to Write Tests: A Love Letter to Factories

Hello there and welcome to an article I've wanted to write about factories for a very long time. This article is really a love letter to the humble factory. As a pattern it could not be simpler, yet it is the most powerful and paradoxically the most underused pattern when writing tests. An ambitious statement, let's dig in and see where we get. ## What is a Factory Ok, so this seems really basic and I imagine there are a lot of rolling eyeballs right now, but let's go through the definition I'm using, just so we're all on the same page. A factory is something that creates an object in a certain state. Factories return scalar value...
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Estimating software: How to deal with requests for estimates

A question that often comes up in conversation with other developers is "How do I deal with requests for estimates?". Usually the person asking the question is frustrated, they know that any estimates they create are pure fiction, yet management keeps asking for them anyway. Then they ask the real question; "How do you make them stop?". Well, I usually give the same answer, "You don't.". Instead you need to ask why are they asking for estimates in the first place. What problem are estimates solving for them? Once you understand that you can figure out the best way to help. ## Why we're asked for estimates When I listen to develop...
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Template Driven Development: Why it doesn't work

Software development is hard, and there have been many attempts to simplify the process over the years, some good, most bad. I'd like to discuss one of the bad attempts, a recurring problem I've seen in software development that myself and my friends have dubbed "Template Driven Development" (the bad TDD). Template Driven Development is the practice of reducing software development down to a series of templates that developers should follow. Developers are given a user story and a rigid schema for how their system should be structured, they are to use a set of pre-defined patterns that they must follow when modelling concepts in th...
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Introducing DDD to your Company

The following are my notes from the last DDD IE meetup, [6th June 2019](https://www.meetup.com/Domain-Driven-Design-Ireland/events/261668803/), on how to introduce DDD to your company. This post is about the concepts we discussed and discussions we had around the topic. There's some great stuff in here, the kind that can only happens through discussion and collaboration. First off, the meetup itself was structured as half talk, have group discussion, with discussion interspersed throughout the slides. We've done a few of these style of meetups in the past and they've worked out really well. Here are the slides: https://slides.com...
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Folder Structure and Frameworks: What is exerting control?

Recently I've been thinking about folder structures, specifically how we structure our web apps to encourage the design we want and to enable other developers to explore and understand the codebase. This train of thought was spurred by a problem we faced with one of our apps, which I'll go into shortly. ## Folders Give Context When we open up an application the folder structure is the first thing we see, even before we glance down at the readme. It conveys the hierarchy of concepts and hopefully how they relate to each other. A haphazard folder hurts more than it helps, especially if you have to hop around from folder to folder. Ch...
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Notes from Working Effectively with Legacy Code

Do you work with Legacy code? You probably do and don't realise it. IMO, if the code is over 5 years old, messy and it makes money, then it's probably legacy. Legacy code is tricky, and most of us try to avoid it, moving onto sexy new ideas and projects as time moves on. This means that we never learn to deal with legacy, and all the while, the codebase is chugging along, getting worse and increasingly expensive to change. If we don't learn to deal with legacy code, then we'll never learn how to maintain systems over time. We need to address this. That's where this article comes in, it is a collection of my notes from reading and a...
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Managing projectors is harder than you think

We've discussed the [bones of projectors in the past](/blog/projection-building-blocks-what-you-ll-need-to-build-projections), this time let's go deeper and look at how to manage them. At it's simplest a projector is something that takes in a stream of events and does some work on them, projecting them into whatever shape or operation is needed. Like anything though, there's more to it than that, lots more. That's what this article is, my attempt to discuss the complications and problems you will run into while working with projectors day to day. # Run modes Let's start simple, let's talk about the different modes of projectors a...
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Domain Driven Design for Everyone Else

I've been talking a lot about Domain Driven Design (DDD) lately, be it at meetups or with clients, so I thought I'd write down my thoughts and see if it helps. Now, lots of people have written about DDD from a technical perspective (see the end for links), so I'm not going to do that, instead I'm going to discuss DDD from a non-technical perspective. This is DDD for everyone else. ## Solutions Always Overrun Designing and building a solution is not a trivial problem. It never goes smoothly, and even if it's completed on time (which is never) the solution is usually ineffective and needs to be changed, often drastically. This lea...
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