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

Website Speed
Speed seems like a small issue to worry about, right? The speed of your website affects every metric you care about. Bounces, rankings, conversions, usability and most important, MONEY in your clients bank account.

Backups
How often should you be backing up your website? What is the maximum acceptable of data loss after a disaster?
It is easy to forget about the risks that face your website until you are obviously hacked and your defaced homepage reminds you that you should have backed up recently.

The ability to fully recover your websites and the process to restore websites are often not thought about in business or web companies.

Confess to us your biggest moment of WP fail?

This is a success story, with an unexpected failure and direct quote from a client:

“Thanks to all your hard work, we had so much traffic last week that OSC server had to shut my site down, something with the bandwidth. Our IT guy said that was because too many people were entering the site and said I needed to update my hosting, more data etc., I don’t know all the lingo… But anyway we canceled service with OSC and went with Amazon server.

I have been the on the first or second spot on the first google page consistently ever since you started working your magic dear & I have to say that we are so impressed with your ability.”

Favorite plugin?

Better WP Security, and WordPress SEO by Yoast.

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

Security:

There is a plethora of security advice for wordpress websites to prevent them from being hacked. It is very important to realize that website security is a process and not a single task, and that the only completely invulnerable site is one that is offline. I feel these best practices need to start in the community, and an easy place to find vulnerable plugins.

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

Q: Do you prefer to work alone or on a team?

At watchful.li, our work environment requires team-oriented developers. Our projects include close interaction with other developers, project managers, and marketers. There are many developers that prefer to work solo, and it works for them. Make sure every developer you interview fits your work environment needs.