What performance tips would you give to other pros (as related to speed, scalability, security, plugins, backup, etc.)?

Security: pick a few plugins that you know and trust – find your favorite hard-core-nerd-php programmer and ask them to take a look at them. Tell them to look for holes? 🙂 Then, provide beer.

If you were going to spend this weekend creating a plugin that doesn’t exist, what would it be?

I would like to create a plugin that was more of a ‘setup’ wizard – to be used after the first install. It would hijack the entire site after install, and give the user some choices: just blog, blog + products, etc. Then it would give some common themes to install, and some plugins. I’m sure similar things like this already exist, but I think a system that had new choices automatically updated and retrieved from the internet would be awesome.

If you could change one thing today about WP, what would it be?

I would want to develop a better system for each plugin, theme, etc, to register its external resources. Never again would you see a site load jQuery 1.9 and 1.8. Common ‘problems’ would be brought up with the plugin – and those plugins would not be accepted into the community until they worked with the resource management.

Tell us a story where you saved the WP day for yourself or on a client project. What made the difference for you?

I had to make a website for a friend that was just purely informational – showcasing a few products. He sent me some sketches and asked for that special favor… you know… its 5p.m. – and I’m going to be showing this tomorrow. What can you get by 8a.m? I’ll tell you what he got: a great, slightly modified theme with product slide show and contact form – and then I went and watched some TV before I went to bed.

If you were interviewing another WordPress developer for a job, what is the first question you would ask and why?

I would ask them to describe their favorite PHP or open source toolkit besides WordPress. I’d want to know that they have experience using other tools besides WP: this way they can be truly certain that WP is the best tool for the job – instead of using it because that’s all they know.