Where I work, we're seeing more professionals (operations engineers, production engineers, accountants, geophysicists, scientists, ...) working on developing their own 'applications' for reporting, visualizations and data analytics.
I thought it'd be good idea to give a talk about software engineering to help them better understand the tools, architecture, trade-offs, ecosystems and such.
Any thoughts on what to include and how to make it more appealing to a wide audience?
Code reviews before checkin.
Tests. ("What is your objective evidence that it does what you need it to do?")
Keeping track of bugs - a bug database, even if somewhat informal.
Handling unexpected input. (For these people, "complain and die" may be a valid approach, but don't just continue and produce garbage output.)
Discussing a variety of languages, and giving some guidance on when to use each, might be useful.