Originally published: July 06, 2025 — Register Spill
My incomplete list of advice for How to Demo:
Tell the audience what problem is being fixed; tell them why you did what you did.
Don’t interrupt yourself.
Don’t let the presentation and your talking go out of sync.
Keep it short.
No, really, keep it shorter.
Call out what’s important! People won’t notice that it’s now a 4000 line file on which you demonstrate your whitespace-analysis tool, you have to call it out and say “watch, this even works on a 4000 line file”
Do not show unnecessary stuff. Don’t go fullscreen-recording if you want to only show your terminal. People will get distracted by your battery levels. They will ask themselves “what is this icon in the menu bar?” instead of listening to you.
You don’t have a laser pointer and you don’t have an index finger — make up for it. Wiggle your cursor, make a selection, select some text. People can’t see what your eyes are focusing on. Show them what they should focus on.
Every frame, every scene: know where the user should look.
Use 1080p.
Bump that font size. And once more.
Don’t say “it’s probably not gonna work” when demo doesn’t aim to show how much of a prototype it is. Because if it then works despite your warning, your audience might miss it — you primed them to focus on things where it won’t work.
Pictures are worth a thousand words. You reduced logs the logs ingested by the system by 100x? Don’t just say that. Show the dashboard before and after. Show disk usage before and after.