User Interface development


Hi, I’m Lex. I was one of Facebook’s first User Interface Engineers. I engineered the homepage, user signup, and many other nifty things related to user growth.

Sign Up

The Facebook signup flow went through many rounds of design changes to increase signups. We a/b tested font sizes, colors, mandatory fields, field ordering, multi-page signup, simplified signup, button colors, copy changes, and more to arrive at what you see today.

However, the very first change I made to registration was to rewrite its Javascript to convert the form from a standard synchronous request to an asynchronous request. This meant the page didn’t need to refresh upon form submission. As a result, form submission was faster, resulting in a sizable bump in registrations, especially in countries with low bandwidth.

New User Experience

Following signup, users were sent through a series of steps which encouraged them to complete their Profile as best as possible. This is called the “NUX” flow.

Profile completeness has a strong effect on the viral nature of Facebook’s growth. New users with complete profiles can be recommended to existing users with better accuracy. The more friends a new user is connected to, the more likely they are to continue to use Facebook.

I was the owner of this experience along with a collection of others. I worked exclusively for the Growth Team for 4 years and was responsible for the for the first 10 minutes of time that a user spent on Facebook.

Profile Page

Once a user finishes the NUX flow, they arrive at their Profile page.

Much of the work done here revolved around encouraging the user to add more information to their profile via callouts and by highlighted certain fields. I also experimented with emphasizing to the user how empty a section looked without any information.

Profile blank state design treatments


Set your profile picture

Many of the steps in the New User Flow required me to design and engineer multiple options. Each would be a/b tested against millions of real users. The winning design would then be launched to 100% of users.

Sometimes the slightest design change can have a tremendous effect on the usability of an interface. Can you guess which of the 3 treatments to the left performed the best?

Contact Importer Campaign

The Growth team wanted to display an ad of sorts to all users on Facebook. The goal of the ad was to get the user to use the contact importer. The ad would show just once to each user, which at the time was around 400 million. I designed many different treatments.\

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