Running a wallet demo live, in front of a room

A live wallet demo breaks in ways rehearsal hides: conference wifi, a balance that moved overnight, twenty seconds of dead air waiting on a confirmation. Fix what you can before you walk in.

Published: 22 September 2026 · Last reviewed: 25 September 2026

What fails in the room, not in rehearsal

A crypto wallet demo has more moving parts than the slide before it, and most of them belong to somebody else. Venue wifi is shared with four hundred laptops, so a price feed times out and the fiat column renders as dashes. A real balance moved overnight, so the figure you rehearsed is not the figure on screen. A send waits on a chain: an Ethereum block is twelve seconds and nobody treats one block as settled, a Bitcoin block averages ten minutes. None of that is a bug. It is a live system behaving normally at the one moment you cannot pause it.

Fix everything that can be fixed in advance

• The values. Tokens, quantities, the day's change, account name, accent colour. Set once, then not touched again.
• One image per beat. A frame for each thing you say, numbered in speaking order.
• Local files. On the machine driving the screen. Not a cloud folder, not a shared drive, not a link.
• The phone, if you mirror one. Do Not Disturb on, auto-lock off, brightness fixed, rotation locked.
• The fallback. Even when you plan to run live software, keep the exported frames one keystroke away.

The projector arithmetic

Screenshot the wallet on a 6.1-inch iPhone and the picture is 1179 × 2556 px. The room is almost always 1920 × 1080. Fitted to the height, that phone is about 500 px wide — a quarter of the screen. Everything on it shrinks by the same factor of 0.42, so text that is comfortable at arm's length is unreadable from row twelve. Crop to the rows that carry the point, pair the phone with text instead of centring it, and say the numbers out loud rather than pointing at them.

Movement you control

A frozen screenshot reads as a slide, and a room can tell. In a composed screen the market prices are real and refresh every few seconds, so the fiat column moves while you talk and the screen behaves like an application. The quantities behind it are typed and do not move, so the sentence you rehearsed still matches what is on the wall. If the venue wifi drops, the prices simply freeze at their last value: the quantities, and your script, do not move.

That is the trade a real account cannot make: movement without a story that changes under you. It stays a mockup — it holds nothing, reaches no chain and signs nothing.

When it has to run for real

Composed screens answer questions about the interface, none about the software. An integration check, a signing flow, latency under real conditions, an acceptance pass with a client, a bug reproduced in front of the person who reported it — all of those need the code running, and no picture substitutes.

Then plan the failure instead of hoping past it: a wired connection or a hotspot tested in that room, an account funded the day before, and a stated exit. If it has not confirmed in fifteen seconds, you keep talking and show the frame.

Say what it is, once

One sentence, early: these are composed screens, the numbers are ours. It costs two seconds and removes the question that lands in the Q and A otherwise. The image is not evidence of funds, and no caption makes it one.

Questions

Should I run the real app or show composed screens?

It depends on the question the room is asking. If it is what the interface looks like and how the flow reads, composed screens carry it and nothing can fail mid-sentence. If it is whether the software works — signing, latency, an integration — you have to run it, and you budget for it: a wired connection, an account funded the day before, and the exported frames one keystroke away.

What should I export for a projector?

Crop before you export. Fitted to a 1080p projector, the whole phone takes about a quarter of the screen width, and small type is gone by the third row of seats. Export one frame per beat of the script, each cropped to the rows that sentence needs, numbered in speaking order, and kept on the machine driving the screen. Read the amounts aloud.

Why not just mirror a real wallet from my phone?

Because everything on it is outside your control for the next forty minutes. The balance moves while you talk, notifications land on the mirrored screen, and an address on a four-metre wall is public permanently — anyone photographs it and an explorer returns the full history. Spam tokens arrive at it afterwards and show up in your app at the next demo.