Two weeks ago, I had the great honor of giving a keynote at the Dutch PHP Conference. Because I had never been to Amsterdam or to the Dutch PHP Conference, I was really excited to have a chance to speak there. It was also an opportunity to give my favorite talk to a new audience.

On the morning of the keynote, I followed along with conference organizer Lorna Mitchell to the RAI Center where the conference was being held. As soon as I saw the stage, I smiled. Not only would I be able to stand on a stage unobstructed by a podium or any other obstacle, the seats were arranged like a theater, making it easier to connect with the audience. (Conference organizers, please take note.)

As I began speaking, I noted that PHP had just turned 15 years old. Years ago, the community was energized by all of the misinformation being spread about PHP. It doesn't scale. It's insecure. It's not maintainable. When I began speaking about security, it was partly in response to some of this. I wanted to educate developers, so that we would not only take responsibility for the security of our apps, but also so that we could avoid the most common and dangerous security problems.

These days, petty insults probably continue in the comments on Digg or Hacker News, but no one takes them too seriously. Can PHP scale? Well, the biggest and most popular sites on the Web all use PHP, so I guess so. With no misinformation to energize us, it can easily seem like the PHP community has lost its luster. Not so.

In my talk, Security-Centered Design, I suggest we take a lesson from the design community, where user experience takes priority. We must evolve, or as Aral Balkan puts it:

The age of features is dead; welcome to the age of user experience.

My talk revolves loosely around security, but it's really a call to arms for my developer peers to take a step back and consider the bigger picture. We need to zoom out. Sometimes, even with a subject as technical as security, the social elements of the problems we face are just as important as the technical. If we can't empathize with users, we can't be great developers.

I want to thank everyone who took the time to say nice things about my talk. Hearing it described as the "best keynote I have ever seen" and the "highlight of the event" is really encouraging and makes it all worthwhile. I can't possibly thank you enough.

I'll leave you with a little taste of the talk where I invite everyone to participate in a change blindness experiment. I may discuss change blindness and how it applies to the Web in more detail later, but for now, see if you can spot the difference in the two photos I used in the change blindness video I created for this talk.

Thanks again to everyone who woke up early after a late night at the conference social to see me speak, and I hope to see you again sometime. :-)