SOFTWARE DESIGN PRINCIPLES

2 days

Structure your code to make changing it to meet future requirements easier, with or without AI coding assistants.

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New Year's Offer

Training bookings confirmed by January 31st are HALF-PRICE

Confirm any Codemanship course booking by January 31st 2026, to be delivered remotely before May 31st, and get 50% off

Poorly designed software is a barrier to change, and therefore a blocker for agility.

On his course, you will learn to structure your code to make change easier, and get plenty of practice at refactoring bad code to make it simpler and more modular.

With an emphasis on the practical, this workshop is packed full of hands-on demonstrations (20%) and exercises (80%). Participants learn together with pair and mob programming.

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Available Online & On-Site

High-quality instructor-led training remotely for groups of up to 12 worldwide and in-person for groups of up to 20 in the UK & EU.

In This Workshop...

Refactoring Foundations

Learn to fix design problems without breaking the software

Simple Design

Learn the 4 principles of Simple Design, and when to trade off one principle against another:

* The code must work
* Code communicates intent
* Code is free of duplication (D.R.Y.)
* Code is as simple as we can make it (YAGNI)

Modular Design

Learn the 4 principles of Modular Design:

* Modules should do one job
* Modules should hide their inner workings
* Modules should have swappable dependencies
* Interfaces should be designed for clients

Learn how to measure modularity and make evidence-based design and refactoring decisions:

* Coupling & Cohesion
* Dependency Polymorphism

Learn how these 4 principles map to S.O.L.I.D. principles for object oriented design.

* Single Responsibility
* Open-Closed
* Liskov Substitution
* Interface Segregation
* Dependency Inversion

Learn the 2 fundamental design idioms that enable modular design:

* Dependency Injection
* Inversion of Control

...and how more modular code tends to be more testable and more portable

Scaling Design Principles

Learn how principles of Modular Design can be applied to component-based and service-oriented architectures, and how they map to the principles of Package Design:

* Release-Reuse Equivalency
* Common Closure
* Common Reuse
* Stable Dependencies
* Stable Abstractions

Learn how to measure modularity at multiple levels of code organisation and make evidence-based decisions on architecture and design:

* Package coupling & cohesion
* Martin Metrics for package dependency polymorphism

Design Principles & AI

Large Language Models like Claude Opus and GPT-5 are very good at generating code that they're pretty bad at modifying. When it comes to architecture, Actual Intelligence must be applied.

* Code clarity & LLM performance
* Complexity & Out-Of-Distribution "hallucinations"
* Separation of Concerns - the secret sauce (again)
* Ground Truth: why "guardrails" don't work
* Continuous Inspection in AI-assisted development
* Refactoring revisited

Video Demo

Check out our free videos on software design principles

Languages

This course is available in C# and Java versions (JavaScript and Python coming soon)

Pricing

Prices are per person, and do not include travel expenses and VAT.

Pricing Band	£ (remote*)	£ (on-site**)
First 4-6 people	~~950~~ 475 until Jan 31st	1150
Next 7-12 people	~~700~~ 350 until Jan 31st	900
Next 13-20 people*	N/A	650
Additional people on the day	950	1150

Minimum number for all training is 4

* Maximum number for online training is 12

** UK & EU only. Maximum number for on-site training is 20

FAQ

Who should attend?

This training workshop is aimed at C# and Java developers with at least one year's experience programming in their chosen language. It's often attended by technical leaders who wish to keep their code craft skills up-to-date, too.

What should I bring?

You will need a suitable computer with your favourite C# or Java editor/IDE installed. On-site courses will require a room large enough to comfortably accomodate all participants, good, reliable Internet access (Wi-Fi), and a data projector or suitably large TV (with HDMI input) that will allow participants to read code from the back of the room. You will find a pen and paper handy.

Where is this training available?

Online training is available whereever you are, pretty much. (There are a few countries it's sadly not possible to do business with, of course.) Onsite training is available across the UK. Ask us.

Who will be our trainer?

9/10 times, the trainer will be Codemanship founder and course author Jason Gorman. Jason has 38 years' programming experience and three decades of professional experience as a developer, technical lead and software architect. He's run hundreds of code craft training workshops over the last 20 years, and is a very experienced teacher and mentor. If, for any reason, Jason isn't available for your workshop, we'll inform you well in advance and offer you a trainer of similar industry seniority.

Will I need to write code in this workshop?

Yes. You will most definitely be writing code in this workshop. Business analysts, testers, project managers etc may find it useful to sit in and observe -at no charge - if they want to gain an understanding of Test-Driven Development and how it fits into the overall software development cycle, but this is 100% a hands-on workshop.

Is it available for other languages?

Since 2009, we've delivered training for developers working in C++, Swift, Go, Kotlin, Groovy, Ruby and many other languages. Ask us about customised courses.