That's story of my life (lead front-end for a while who has to report to the demanding non tech-savy client/stakeholder most of the times..), so I told them the most basic and most effective (at least according to my experience) way of passing that message: with a working demo/example.
Technical part A: Code review. The task was to review simple app consisting of 3 forms that accept name/age and rearrange them based on the age (higher to lower). It was consisting of 2 files (HTML/CSS, JS).
Technical part b: Software Architecture planning. A simple article (one article) editing app that was feeding text+images into a server (2 databases, image and text). Very enjoyable example and really intriguing as it made your brain to think!
You were free to choose your database structure so I chose a noSQL for efficiency. The brief was to make the above work while using the following criteria: a) Multiple users should be able to live edit at the same time the same article. b) The article-draft should be accessible even if the internet drops.