PHP in Real Projects: Cases of Large Companies and Lessons for Developers

PHP in Real Projects: Not a Myth, but a Battle-Tested Tool of Giants

When you hear "PHP," images of old forums or custom-built online stores often come to mind. But let's be honest: PHP in real projects is not just legacy code. It's the language that powers Facebook (partially), Wikipedia, Slack (initially), and Etsy. They chose it not out of desperation, but because it solves their problems.

In this article, we will break down real company cases that used PHP. You will see code examples, learn how they tackled bottlenecks, and most importantly — what lessons you can apply to your own projects. Let's go!

Why Don't Large Companies Shy Away from PHP?

PHP has come a long way. Version 8.x with JIT compilation and strict typing has turned it into a serious backend language. The main reasons giants stick with PHP:

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• Rapid development. PHP allows you to write code quickly — this is critical for startups.
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• Huge community. Any problem has already been solved by someone. Composer, Laravel, Symfony — the ecosystem is mature.
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• Horizontal scaling. PHP can easily be cloned across hundreds of servers.
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• Legacy code. Sometimes rewriting everything in Go or Python is a luxury that companies cannot afford.
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Case #1: Facebook (Meta) — HipHop and HHVM

In the 2010s, Facebook faced a problem: PHP code was growing exponentially, and the standard interpreter couldn't handle the load. Mark Zuckerberg's engineers took an unconventional path — they created HipHop for PHP, and later HHVM (HipHop Virtual Machine).

The idea: transpile PHP into C++ and compile it. This gave a 5-6x performance boost. Later, HHVM became a virtual machine with JIT compilation. Around the same time, PHP 7 emerged, solving some of the problems at the language level.

Lesson for us: If your PHP project is slow, don't rush to rewrite it in another language. Try optimizing the code, using OPcache, and for the heaviest parts — write a C extension or upgrade to PHP 8.x.

Example: How Facebook Accelerated Array Processing

<?php\n// Problem: slow iteration over a large array\n$users = getUsersFromDB(); // 1 million records\nforeach ($users as $user) {\n    processUser($user);\n}\n\n// Solution: use generators and chunks\nfunction getUsersChunked(int $chunkSize = 1000): Generator {\n    $offset = 0;\n    while (true) {\n        $chunk = getUsersFromDBWithLimit($chunkSize, $offset);\n        if (empty($chunk)) break;\n        foreach ($chunk as $user) {\n            yield $user;\n        }\n        $offset += $chunkSize;\n    }\n}\n\nforeach (getUsersChunked() as $user) {\n    processUser($user);\n}\n?>

This pattern reduces memory consumption and speeds up execution by working with small batches of data.

Case #2: Slack — PHP at the Start and a Hybrid Transition

Slack started as a PHP application on the CodeIgniter framework. The team quickly realized that for a real-time chat, they needed more than just PHP. But instead of a full rewrite, they built a hybrid architecture: PHP remained for the web and API, while real-time logic was moved to Erlang and later to C++.

Interesting fact: a significant portion of Slack's backend is still written in PHP. They simply moved performance-critical tasks to separate microservices.

Lesson for us: You don't have to divide the world into "PHP — bad, Go — good." Use PHP where it excels: CRUD, admin panels, database work, integrations. For websockets, queues, and heavy computations, bring in specialized tools.

Example: Integrating PHP with RabbitMQ for Asynchronous Message Sending

<?php\nrequire_once __DIR__ . '/vend