Finding programming challenge for a (probably) Qt project with tight time frame (interview level)

Question

Dear stackoverflow: What would you suggest would be a good challenge for a programmer to show us her/his skills? I'm thinking of a small demo implementation of a GUI program which would not take too much time to do.

Here are the circumstances: (this should not imply the intention to find programmers here, I think there'd be other forums to do that)

We are planning a project which has a tight time frame but apparently we are short on resources so we want to pull in external developers. The project is targetted to be Qt based (although this is not yet finally set) on the Windows platform. We'd prefer Qt as this allows to use own resources later when features need to be added to the software and we are familiar with the Qt platform.

The project needs to interface with HID USB hardware (writing some data blocks out, reading back the result, within to be guaranteed time frames) and a GUI showing graphs of the analyses.

The main intention however is not to find a Qt programmer (although we would prefer that) but a capable programmer - thus the important part of this question is about the challenge.

Answer 1

Don't ask programmers to write something from scratch as an interview task. It's far too suspect.

Think of the qualities that you want in a developer and then write an application that has all of those things done wrong, and ask them to fix it. For example, if you want an Object Oriented developer, give them an application with the data tables directly bound to the UI and ask them to make it OO - it means they can show you in a few minutes that they have OO skills.

By starting with a sample application that is "fixed up" with all the problems, it makes it really easy to compare the results and it will be a much faster test than if you ask people to write something from scratch.

Don't forget to make the test measurable. Score each thing you are testing as well as how long it takes.