What is the difference between a demo and a deployment?
A demo shows that a system can work once, on chosen examples, in front of the people who built it. A deployment works every day, on real data, inside another company's rules, for people who did not build it. Most of the engineering work lies between the two.
Why do demos work so well?
Because everything in a demo is chosen. The examples are picked, the data is clean, and the person at the keyboard knows what to type and what to avoid.
That is not dishonest. A demo exists to show what is possible. The trouble starts when a team plans as if the demo were the product.
What are the gaps between a demo and a deployment?
There are six: the plan, the systems, the data, the checks, the tests and the handover. Each one is easy to skip in a demo and impossible to skip at a customer.
1. The plan
In a demo the problem is already clear. At a customer, someone has to turn "we want AI for support" into one page that says what done means, and get it agreed.
2. The systems
The demo ran on your laptop with your tools. The deployment runs in the customer's cloud, behind their login, next to systems you did not build and cannot rewrite.
3. The data
Demo data is a small, clean sample. Real data is messy and incomplete, with access rules. Fields are missing, formats change, and some of it you are not allowed to see.
4. The checks
Nobody in a demo asks where the data goes. At a customer, the security, privacy and compliance teams ask exactly that, and the system does not go live until they agree.
5. The tests
A demo is judged by whether it looked right in the meeting. A deployment is judged by tests agreed with the people who will use the system.
6. The handover
When a demo ends, the laptop closes. A deployment needs documents, monitoring and a named owner, because the system must keep working after you leave.
Who closes the gaps?
An engineer who works inside the customer's company until the system is in daily use. That job is called forward deployed engineer.
It is an engineering job first: the person writes code every week. What changes is where the requirements come from: a person you work with, not a ticket. The guide What is a forward deployed engineer? explains the job in full.
How can a team tell which one it has?
Ask five questions. If the answer to any of them is no, you have a demo. That is fine, as long as the plan says so.
- Has it run on data we did not pick?
- Has someone outside the team used it without help?
- Is there a written test it must pass?
- Do we know what one use costs?
- Is there a name next to "owner after launch"?