BCS SPA specialist group


Kevlin Henney

Please note: Due to unforeseen circumstances the speaker Kevlin Henney is unable to talk live this evening but we have provided a pre-recorded version of Kevlin's talk dated 15 September 2020. The AGM will still start at 6:15


  • from 6:00pm: log in, wait for webinar to begin
  • 6:15pm: SPA SG Annual General Meeting (SG members only, not recorded)
  • 6:30pm approximately: Pre-recorded presentation - speaker is unable to make a live appearance tonight.
  • 8:00pm approximately: Q & A
  • 8:15pm approximately: end


It is not enough that software works as desired and expected. We place a great deal of value on its internal quality, citing the comprehensibility of the code and the clarity of its intent as hallmarks of that quality. We separate concerns and structures in order to understand and reason about our code. Domain-driven design seeks to distil our understanding of the domain into the structuring of code, creating a correspondence between the world of the problem and the world of the solution.

But what if such modularity and modelarity does not exist in the design or in the domain? What if the failure modes of software are not based on mechanisms structured for our understanding? Whether we are talking optimising compilers, machine learning or the interactions of software with people and other systems, not everything about the software is reasonable or can be reasoned about easily.

About the speaker

Kevlin Henney is an independent consultant, trainer, reviewer and writer. His development interests are in programming, people and practice.

He has been a columnist for various magazines and websites, a contributor to open-source software and a member of more committees than is probably healthy (it has been said that "a committee is a cul-de-sac down which ideas are lured and then quietly strangled"). He is an author of two volumes in the Pattern-Oriented Software Architecture series and editor of 97 Things Every Programmer Should Know and 97 Things Every Java Programmer Should Know.

Our events are for adults aged 16 years and over.

This event is brought to you by: BCS SPA group

Webinar: Unreasonable architecture
Date and time
Wednesday 4 November, 6:00pm - 8:00pm
This event is sold out