PyCon UK 2025

Principle Misunderstandings
2025-09-20 , Space 2

For developers who want to improve their art there's no shortage of published, promoted and proclaimed principles they can choose from to shape their style and craft their style. In this talk we'll take a look a few, highlighting the real lessons we can apply to our code.


For developers who want to improve their art there's no shortage of published, promoted and proclaimed principles they can choose from to shape their style and craft their style. Whether it's the alphabet soup of SOLID principles or old school classics like Information Hiding and the Separation of Concerns, there's a lot of advice out there. Some of it even makes sense. And some of it is well supported. But a lot of principles are misunderstood, misapplied or simply mistaken.

In this talk we'll take a look (and take down) a few principles, highlighting the real lessons we can apply to our code — lessons supported by sound rationale rather than just strong opinions.


What level of experience do you expect from your audience for this session?:

Intermediate

Kevlin Henney is an independent consultant, speaker, writer and trainer. He is co-author of A Pattern Language for Distributed Computing and On Patterns and Pattern Languages, two volumes in the Pattern-Oriented Software Architecture series. He is also editor of 97 Things Every Programmer Should Know and co-editor of 97 Things Every Java Programmer Should Know.