Every now and then there’s still some people who can’t believe PHP can be used for a big, successful project, when actually there are several examples of huge sites using PHP.
Here’s how some of them share their experience.
With over 1.49 billion active users, Facebook has been forced into finding creative, out-of-the-box solutions to scaling.
First, they introduced HipHop for PHP on 2010, a transpiler that took PHP code and converted it into a C++ binary.
Even though the project was largely successful, it forced an elaborate deployment process and several incompatibilities with some PHP language features.
On December 2011, they released the HipHop Virtual Machine (HHVM), an open source virtual machine based on Just-In-Time compilation that allowed the greatly improved performance with an easier development and deployment process.
HHVM helped boost the PHP language development introducing lots of new features and a massive performance improvement on PHP7.
Wikipedia
Wikipedia is probably one of the most visited sites using PHP as programming language and MySQL/MariaDB as their database backend.
On 2014 they switched to HHVM and made everything run nearly twice as fast.
You can check more details on their stack on their technical FAQ.
MailChimp
MailChimp it’s one of the leaders on e-mail marketing. According to their stats, they’re sending (as of 2014) more than 400 million e-mails for their 7 million users using PHP.
In 2010 they posted Ewww, You Use PHP? where they declared that PHP “it’s the only language we use for everything touching the production MailChimp application“.
Tumblr
Tumblr is where memes are born. With over 325 million blogs and 555 million monthly visitors, it’s a huge community.
This year, they switched to PHP7 and posted about the great improvements on performance and the new language features that they’re now able to use, such as return type declarations and scalar type hints.
Slack
Slack is one of the latest, trendiest “unicorns”. The “team communications” app is valued at around 4 billion dollars and it’s used by over 3 million users each day.
Given how it’s a relatively recent project, with such a “cool” vibe and how “uncool” PHP it’s frequently perceived, I must say I was really surprised to learn that they’re using PHP in their backend.
Anyway… they do… and they recently wrote about it on their engineering blog: Taking PHP seriously.
DailyMotion
Dailymotion it’s one of the few YouTube-alternatives that not only have survived, but also has managed to stay relevant. They stream 3 billion video views per month to over 300 million users.
On 2015 they started to experiment with HHVM but ultimately chose to deploy PHP7 for an easier migration and better performance and stability.
Etsy
Etsy is one of the top ten most popular retail websites in the US with over 54 million registered users and more than 19 million buyers, making it one of the largest e-commerce sites built on PHP.
They have documented their experimentation with HHVM in search for performance optimizations and even got Rasmus Lerdorf, the creator of PHP, giving a talk about PHP7 deployment.
On top of that, they released Phan, a static analyzer that can detect incompatibilities between PHP5/7 and many more issues that might cause problems.